[time-nuts] GPS Spoofing

[J. Forster]

Prof. Humphry from Texas just reported being able to spoof GPS in the Med
and take over the nav system of a luxury yacht. He's done this before with
a drone in the US.

LORAN as a backup, at least?

-John

==



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Re: [time-nuts] GPS Spoofing

[Chris Albertson]

I boat?  The backup is a competent captain.  He'd see the compass heading
move and quickly disengage the autopilot.   I had a boat for years  I'd
notice a 5 degree change.  Mine was a sailboat so I'd be more sensitive to
heading changes than a power boater but still the human is the backup.

Most autopilots don't directly follow GPS, they use GPS to determine a
heading, follow it then use GPS to detect drift and re-compute the heading.
 the heading would be held by a compass sensor in a low-cost setup or in a
larger setup a lazer ring gyro backed up by a compass. So a spoofed GPS
would cause the autopilot to "think" there was a bigger crooswnd or current
and make a bigger heading change.

I bet you could hijack a drone not a manned vehicle the pilot is trained to
monitor the automation and he'd very quickly turn it off thinking it was
broken.






On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:

> Prof. Humphry from Texas just reported being able to spoof GPS in the Med
> and take over the nav system of a luxury yacht. He's done this before with
> a drone in the US.
>
> LORAN as a backup, at least?
>
> -John
>
> ==
>
>
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 

Chris Albertson
Redondo Beach, California
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Re: [time-nuts] GPS Spoofing

[J. Forster]

I gather from the article, the GPS position was spoofed and the autopilot,
in bringing it back to where it was supposed to be, actually took it off
course.

There are places where a few hundred feet makes a big difference, viz. the
Costa Concordia.

IMO, this is a very convincing reason for something like LORAN.

-John

=



> I boat?  The backup is a competent captain.  He'd see the compass heading
> move and quickly disengage the autopilot.   I had a boat for years  I'd
> notice a 5 degree change.  Mine was a sailboat so I'd be more sensitive to
> heading changes than a power boater but still the human is the backup.
>
> Most autopilots don't directly follow GPS, they use GPS to determine a
> heading, follow it then use GPS to detect drift and re-compute the
> heading.
>  the heading would be held by a compass sensor in a low-cost setup or in a
> larger setup a lazer ring gyro backed up by a compass. So a spoofed
> GPS
> would cause the autopilot to "think" there was a bigger crooswnd or
> current
> and make a bigger heading change.
>
> I bet you could hijack a drone not a manned vehicle the pilot is trained
> to
> monitor the automation and he'd very quickly turn it off thinking it was
> broken.
>
>
>
>
>
>
> On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:
>
>> Prof. Humphry from Texas just reported being able to spoof GPS in the
>> Med
>> and take over the nav system of a luxury yacht. He's done this before
>> with
>> a drone in the US.
>>
>> LORAN as a backup, at least?
>>
>> -John
>>
>> ==
>>
>>
>>
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
>
>
> --
>
> Chris Albertson
> Redondo Beach, California
>


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Re: [time-nuts] GPS Spoofing

[Jim Lux]

On 7/26/13 8:45 PM, J. Forster wrote:

I gather from the article, the GPS position was spoofed and the autopilot,
in bringing it back to where it was supposed to be, actually took it off
course.

There are places where a few hundred feet makes a big difference, viz. the
Costa Concordia.

IMO, this is a very convincing reason for something like LORAN.


I think it's a convincing argument for a captain who pays attention to 
the other navigation instruments and doesn't blindly follow the GPS.


It's also a convincing argument that shipboard 
automation/autopilot/autocontrol vendors need to make more sophisticated 
software (which I suspect they do, particularly on 200+ foot ships.. I 
would imagine that there are some aspects of this demo that are 
contrived.)  The ship making and driving business is pretty unregulated. 
It's all about what the owner of the ship is willing to pay (or what he 
needs to get liability insurance, if he wants).  There's nothing even 
remotely like DO-178 for shipboard stuff.


The folks doing stabilized oil rigs probably have sophisticated systems, 
but they're also using IMUs and other stuff. Ditto for high value things 
(oil tankers, warships).  Molasses tankers? They're probably lucky to 
have a functioning compass and some old charts.



I'm not sure, though, that looking at the big picture, whether your tax 
dollars are better spent on LORAN, or on some other precision navigation 
method or on making jam resistant GPS receivers (which do, in fact 
exist, and make use of things like direction of arrival of the signal..)


Note that a GPS system with 3 antennas (as is common in systems that use 
GPS to derive attitude/orientation) would be extremely difficult to 
spoof, and would be VERY inexpensive to implement.  Either the carrier 
phases and code phases are consistent for all the received signals or 
they're not.  A jamming signal coming from the wrong direction will not 
have the right direction of arrival relative to the platform 
orientation.  One wrong signal might be tolerable (multipath, etc.) but 
with a multi satellite fix, I suspect it would be hard to do it.


Sure, one could throw up N pseudolites on a bunch of UAVs, etc., but 
that's getting to be a bit noticeable.



For what it's worth, I don't know that LORAN has the performance to 
avoid a Costa Concordia type foul up (assuming they were crazy enough to 
do the near pass in the fog, so visual navigation didn't work)


I seem to recall that LORAN had 1/4 nmi kinds of accuracy.  it would get 
you to the channel or mouth of the harbor, but not get you into your 
berth. You might be familiar with the local propagation anomalies and 
get better accuracy with experience in your local waters.









-John

=




I boat?  The backup is a competent captain.  He'd see the compass heading
move and quickly disengage the autopilot.   I had a boat for years  I'd
notice a 5 degree change.  Mine was a sailboat so I'd be more sensitive to
heading changes than a power boater but still the human is the backup.

Most autopilots don't directly follow GPS, they use GPS to determine a
heading, follow it then use GPS to detect drift and re-compute the
heading.
  the heading would be held by a compass sensor in a low-cost setup or in a
larger setup a lazer ring gyro backed up by a compass. So a spoofed
GPS
would cause the autopilot to "think" there was a bigger crooswnd or
current
and make a bigger heading change.

I bet you could hijack a drone not a manned vehicle the pilot is trained
to
monitor the automation and he'd very quickly turn it off thinking it was
broken.






On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:


Prof. Humphry from Texas just reported being able to spoof GPS in the
Med
and take over the nav system of a luxury yacht. He's done this before
with
a drone in the US.

LORAN as a backup, at least?

-John

==



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--

Chris Albertson
Redondo Beach, California




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Re: [time-nuts] GPS Spoofing

[David McGaw]

LORAN can be good to 60 ft.


On 7/27/13 12:21 AM, Jim Lux wrote:

On 7/26/13 8:45 PM, J. Forster wrote:
I gather from the article, the GPS position was spoofed and the 
autopilot,

in bringing it back to where it was supposed to be, actually took it off
course.

There are places where a few hundred feet makes a big difference, 
viz. the

Costa Concordia.

IMO, this is a very convincing reason for something like LORAN.


I think it's a convincing argument for a captain who pays attention to 
the other navigation instruments and doesn't blindly follow the GPS.


It's also a convincing argument that shipboard 
automation/autopilot/autocontrol vendors need to make more 
sophisticated software (which I suspect they do, particularly on 200+ 
foot ships.. I would imagine that there are some aspects of this demo 
that are contrived.)  The ship making and driving business is pretty 
unregulated. It's all about what the owner of the ship is willing to 
pay (or what he needs to get liability insurance, if he wants).  
There's nothing even remotely like DO-178 for shipboard stuff.


The folks doing stabilized oil rigs probably have sophisticated 
systems, but they're also using IMUs and other stuff. Ditto for high 
value things (oil tankers, warships).  Molasses tankers? They're 
probably lucky to have a functioning compass and some old charts.



I'm not sure, though, that looking at the big picture, whether your 
tax dollars are better spent on LORAN, or on some other precision 
navigation method or on making jam resistant GPS receivers (which do, 
in fact exist, and make use of things like direction of arrival of the 
signal..)


Note that a GPS system with 3 antennas (as is common in systems that 
use GPS to derive attitude/orientation) would be extremely difficult 
to spoof, and would be VERY inexpensive to implement. Either the 
carrier phases and code phases are consistent for all the received 
signals or they're not.  A jamming signal coming from the wrong 
direction will not have the right direction of arrival relative to the 
platform orientation.  One wrong signal might be tolerable (multipath, 
etc.) but with a multi satellite fix, I suspect it would be hard to do 
it.


Sure, one could throw up N pseudolites on a bunch of UAVs, etc., but 
that's getting to be a bit noticeable.



For what it's worth, I don't know that LORAN has the performance to 
avoid a Costa Concordia type foul up (assuming they were crazy enough 
to do the near pass in the fog, so visual navigation didn't work)


I seem to recall that LORAN had 1/4 nmi kinds of accuracy.  it would 
get you to the channel or mouth of the harbor, but not get you into 
your berth. You might be familiar with the local propagation anomalies 
and get better accuracy with experience in your local waters.









-John

=



I boat?  The backup is a competent captain.  He'd see the compass 
heading

move and quickly disengage the autopilot.   I had a boat for years  I'd
notice a 5 degree change.  Mine was a sailboat so I'd be more 
sensitive to

heading changes than a power boater but still the human is the backup.

Most autopilots don't directly follow GPS, they use GPS to determine a
heading, follow it then use GPS to detect drift and re-compute the
heading.
  the heading would be held by a compass sensor in a low-cost setup 
or in a

larger setup a lazer ring gyro backed up by a compass. So a spoofed
GPS
would cause the autopilot to "think" there was a bigger crooswnd or
current
and make a bigger heading change.

I bet you could hijack a drone not a manned vehicle the pilot is 
trained

to
monitor the automation and he'd very quickly turn it off thinking it 
was

broken.






On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:


Prof. Humphry from Texas just reported being able to spoof GPS in the
Med
and take over the nav system of a luxury yacht. He's done this before
with
a drone in the US.

LORAN as a backup, at least?

-John

==



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--

Chris Albertson
Redondo Beach, California




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Re: [time-nuts] GPS Spoofing

[Robert Atkinson]

It seems you can't rely on the human backup. The UK Marine accident 
Investigation Branch Has recorded numerous accidents due to poor lookout. See
http://www.maib.gov.uk/cms_resources.cfm?file=/KarinSchepersReportWeb.pdf
http://www.maib.gov.uk/cms_resources.cfm?file=/CoastalIsle.pdf
http://www.maib.gov.uk/cms_resources.cfm?file=/Beaumont.pdf
http://www.maib.gov.uk/cms_resources.cfm?file=/Seagate_ReportWeb.pdf
for recent examplesThe other problem is that AIS, a significant anti-collision 
aid, relies on GPS and is susceptable to spoofing.

Robert G8RPI.



 From: Chris Albertson 
To: j...@quikus.com; Discussion of precise time and frequency measurement 
 
Sent: Saturday, 27 July 2013, 4:18
Subject: Re: [time-nuts] GPS Spoofing
 

I boat?  The backup is a competent captain.  He'd see the compass heading
move and quickly disengage the autopilot.   I had a boat for years  I'd
notice a 5 degree change.  Mine was a sailboat so I'd be more sensitive to
heading changes than a power boater but still the human is the backup.

Most autopilots don't directly follow GPS, they use GPS to determine a
heading, follow it then use GPS to detect drift and re-compute the heading.
the heading would be held by a compass sensor in a low-cost setup or in a
larger setup a lazer ring gyro backed up by a compass.     So a spoofed GPS
would cause the autopilot to "think" there was a bigger crooswnd or current
and make a bigger heading change.

I bet you could hijack a drone not a manned vehicle the pilot is trained to
monitor the automation and he'd very quickly turn it off thinking it was
broken.






On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:

> Prof. Humphry from Texas just reported being able to spoof GPS in the Med
> and take over the nav system of a luxury yacht. He's done this before with
> a drone in the US.
>
> LORAN as a backup, at least?
>
> -John
>
> ==
>
>
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 

Chris Albertson
Redondo Beach, California
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Re: [time-nuts] GPS Spoofing

[Brian Alsop]

If you know your LORAN has a 1/4 mile accuracy then you stay 1/2 mile 
away from bad things.


The trouble with GPS is that it is so good, people don't use common 
sense and give obstacles a wide berth.


Brian

On 7/27/2013 04:21, Jim Lux wrote:

On 7/26/13 8:45 PM, J. Forster wrote:

I gather from the article, the GPS position was spoofed and the
autopilot,
in bringing it back to where it was supposed to be, actually took it off
course.

There are places where a few hundred feet makes a big difference, viz.
the
Costa Concordia.

IMO, this is a very convincing reason for something like LORAN.


I think it's a convincing argument for a captain who pays attention to
the other navigation instruments and doesn't blindly follow the GPS.

It's also a convincing argument that shipboard
automation/autopilot/autocontrol vendors need to make more sophisticated
software (which I suspect they do, particularly on 200+ foot ships.. I
would imagine that there are some aspects of this demo that are
contrived.)  The ship making and driving business is pretty unregulated.
It's all about what the owner of the ship is willing to pay (or what he
needs to get liability insurance, if he wants).  There's nothing even
remotely like DO-178 for shipboard stuff.

The folks doing stabilized oil rigs probably have sophisticated systems,
but they're also using IMUs and other stuff. Ditto for high value things
(oil tankers, warships).  Molasses tankers? They're probably lucky to
have a functioning compass and some old charts.


I'm not sure, though, that looking at the big picture, whether your tax
dollars are better spent on LORAN, or on some other precision navigation
method or on making jam resistant GPS receivers (which do, in fact
exist, and make use of things like direction of arrival of the signal..)

Note that a GPS system with 3 antennas (as is common in systems that use
GPS to derive attitude/orientation) would be extremely difficult to
spoof, and would be VERY inexpensive to implement.  Either the carrier
phases and code phases are consistent for all the received signals or
they're not.  A jamming signal coming from the wrong direction will not
have the right direction of arrival relative to the platform
orientation.  One wrong signal might be tolerable (multipath, etc.) but
with a multi satellite fix, I suspect it would be hard to do it.

Sure, one could throw up N pseudolites on a bunch of UAVs, etc., but
that's getting to be a bit noticeable.


For what it's worth, I don't know that LORAN has the performance to
avoid a Costa Concordia type foul up (assuming they were crazy enough to
do the near pass in the fog, so visual navigation didn't work)

I seem to recall that LORAN had 1/4 nmi kinds of accuracy.  it would get
you to the channel or mouth of the harbor, but not get you into your
berth. You might be familiar with the local propagation anomalies and
get better accuracy with experience in your local waters.








-John

=




I boat?  The backup is a competent captain.  He'd see the compass
heading
move and quickly disengage the autopilot.   I had a boat for years  I'd
notice a 5 degree change.  Mine was a sailboat so I'd be more
sensitive to
heading changes than a power boater but still the human is the backup.

Most autopilots don't directly follow GPS, they use GPS to determine a
heading, follow it then use GPS to detect drift and re-compute the
heading.
  the heading would be held by a compass sensor in a low-cost setup
or in a
larger setup a lazer ring gyro backed up by a compass. So a spoofed
GPS
would cause the autopilot to "think" there was a bigger crooswnd or
current
and make a bigger heading change.

I bet you could hijack a drone not a manned vehicle the pilot is trained
to
monitor the automation and he'd very quickly turn it off thinking it was
broken.






On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:


Prof. Humphry from Texas just reported being able to spoof GPS in the
Med
and take over the nav system of a luxury yacht. He's done this before
with
a drone in the US.

LORAN as a backup, at least?

-John

==



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--

Chris Albertson
Redondo Beach, California




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Checked 

Re: [time-nuts] GPS Spoofing

[J. Forster]

About 25 years ago, I bought a bunch of LORAN-C receiver boards at the
Appelco bankrupcy auction. Despite zero doc, I got a couple running.

They had to 8085 uPs, one to compute the TDs and a second,on a daughter
board, to compute Lat/Long. The unit would repeatably hit my location w/in
a couple of hundred feet.

A trivial uP in a box could easily subtract the GPS and LORAN positions
and sound an alarm if they differed by more than a set limit, and sound an
alarm.

Furthermore, I suspect the cost to operate a set of worldwide LORAN chains
is far less than launching a single GPS bird.

-John

==



> LORAN can be good to 60 ft.
>
>
> On 7/27/13 12:21 AM, Jim Lux wrote:
>> On 7/26/13 8:45 PM, J. Forster wrote:
>>> I gather from the article, the GPS position was spoofed and the
>>> autopilot,
>>> in bringing it back to where it was supposed to be, actually took it
>>> off
>>> course.
>>>
>>> There are places where a few hundred feet makes a big difference,
>>> viz. the
>>> Costa Concordia.
>>>
>>> IMO, this is a very convincing reason for something like LORAN.
>>
>> I think it's a convincing argument for a captain who pays attention to
>> the other navigation instruments and doesn't blindly follow the GPS.
>>
>> It's also a convincing argument that shipboard
>> automation/autopilot/autocontrol vendors need to make more
>> sophisticated software (which I suspect they do, particularly on 200+
>> foot ships.. I would imagine that there are some aspects of this demo
>> that are contrived.)  The ship making and driving business is pretty
>> unregulated. It's all about what the owner of the ship is willing to
>> pay (or what he needs to get liability insurance, if he wants).
>> There's nothing even remotely like DO-178 for shipboard stuff.
>>
>> The folks doing stabilized oil rigs probably have sophisticated
>> systems, but they're also using IMUs and other stuff. Ditto for high
>> value things (oil tankers, warships).  Molasses tankers? They're
>> probably lucky to have a functioning compass and some old charts.
>>
>>
>> I'm not sure, though, that looking at the big picture, whether your
>> tax dollars are better spent on LORAN, or on some other precision
>> navigation method or on making jam resistant GPS receivers (which do,
>> in fact exist, and make use of things like direction of arrival of the
>> signal..)
>>
>> Note that a GPS system with 3 antennas (as is common in systems that
>> use GPS to derive attitude/orientation) would be extremely difficult
>> to spoof, and would be VERY inexpensive to implement. Either the
>> carrier phases and code phases are consistent for all the received
>> signals or they're not.  A jamming signal coming from the wrong
>> direction will not have the right direction of arrival relative to the
>> platform orientation.  One wrong signal might be tolerable (multipath,
>> etc.) but with a multi satellite fix, I suspect it would be hard to do
>> it.
>>
>> Sure, one could throw up N pseudolites on a bunch of UAVs, etc., but
>> that's getting to be a bit noticeable.
>>
>>
>> For what it's worth, I don't know that LORAN has the performance to
>> avoid a Costa Concordia type foul up (assuming they were crazy enough
>> to do the near pass in the fog, so visual navigation didn't work)
>>
>> I seem to recall that LORAN had 1/4 nmi kinds of accuracy.  it would
>> get you to the channel or mouth of the harbor, but not get you into
>> your berth. You might be familiar with the local propagation anomalies
>> and get better accuracy with experience in your local waters.
>>
>>
>>
>>
>>
>>
>>>
>>> -John
>>>
>>> =
>>>
>>>
>>>
 I boat?  The backup is a competent captain.  He'd see the compass
 heading
 move and quickly disengage the autopilot.   I had a boat for years
 I'd
 notice a 5 degree change.  Mine was a sailboat so I'd be more
 sensitive to
 heading changes than a power boater but still the human is the backup.

 Most autopilots don't directly follow GPS, they use GPS to determine a
 heading, follow it then use GPS to detect drift and re-compute the
 heading.
   the heading would be held by a compass sensor in a low-cost setup
 or in a
 larger setup a lazer ring gyro backed up by a compass. So a
 spoofed
 GPS
 would cause the autopilot to "think" there was a bigger crooswnd or
 current
 and make a bigger heading change.

 I bet you could hijack a drone not a manned vehicle the pilot is
 trained
 to
 monitor the automation and he'd very quickly turn it off thinking it
 was
 broken.






 On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:

> Prof. Humphry from Texas just reported being able to spoof GPS in the
> Med
> and take over the nav system of a luxury yacht. He's done this before
> with
> a drone in the US.
>
> LORAN as a backup, at least?
>
> -John
>
> ==
>>

Re: [time-nuts] GPS Spoofing

[Scott McGrath]

Key here is how does the captain know that GPS is no longer providing an 
accurate fix?   You need 2 or more independent systems to cross check each 
other.  

Sent from my iPhone

On Jul 27, 2013, at 12:21 AM, Jim Lux  wrote:

> On 7/26/13 8:45 PM, J. Forster wrote:
>> I gather from the article, the GPS position was spoofed and the autopilot,
>> in bringing it back to where it was supposed to be, actually took it off
>> course.
>> 
>> There are places where a few hundred feet makes a big difference, viz. the
>> Costa Concordia.
>> 
>> IMO, this is a very convincing reason for something like LORAN.
> 
> I think it's a convincing argument for a captain who pays attention to the 
> other navigation instruments and doesn't blindly follow the GPS.
> 
> It's also a convincing argument that shipboard 
> automation/autopilot/autocontrol vendors need to make more sophisticated 
> software (which I suspect they do, particularly on 200+ foot ships.. I would 
> imagine that there are some aspects of this demo that are contrived.)  The 
> ship making and driving business is pretty unregulated. It's all about what 
> the owner of the ship is willing to pay (or what he needs to get liability 
> insurance, if he wants).  There's nothing even remotely like DO-178 for 
> shipboard stuff.
> 
> The folks doing stabilized oil rigs probably have sophisticated systems, but 
> they're also using IMUs and other stuff. Ditto for high value things (oil 
> tankers, warships).  Molasses tankers? They're probably lucky to have a 
> functioning compass and some old charts.
> 
> 
> I'm not sure, though, that looking at the big picture, whether your tax 
> dollars are better spent on LORAN, or on some other precision navigation 
> method or on making jam resistant GPS receivers (which do, in fact exist, and 
> make use of things like direction of arrival of the signal..)
> 
> Note that a GPS system with 3 antennas (as is common in systems that use GPS 
> to derive attitude/orientation) would be extremely difficult to spoof, and 
> would be VERY inexpensive to implement.  Either the carrier phases and code 
> phases are consistent for all the received signals or they're not.  A jamming 
> signal coming from the wrong direction will not have the right direction of 
> arrival relative to the platform orientation.  One wrong signal might be 
> tolerable (multipath, etc.) but with a multi satellite fix, I suspect it 
> would be hard to do it.
> 
> Sure, one could throw up N pseudolites on a bunch of UAVs, etc., but that's 
> getting to be a bit noticeable.
> 
> 
> For what it's worth, I don't know that LORAN has the performance to avoid a 
> Costa Concordia type foul up (assuming they were crazy enough to do the near 
> pass in the fog, so visual navigation didn't work)
> 
> I seem to recall that LORAN had 1/4 nmi kinds of accuracy.  it would get you 
> to the channel or mouth of the harbor, but not get you into your berth. You 
> might be familiar with the local propagation anomalies and get better 
> accuracy with experience in your local waters.
> 
> 
> 
> 
> 
> 
>> 
>> -John
>> 
>> =
>> 
>> 
>> 
>>> I boat?  The backup is a competent captain.  He'd see the compass heading
>>> move and quickly disengage the autopilot.   I had a boat for years  I'd
>>> notice a 5 degree change.  Mine was a sailboat so I'd be more sensitive to
>>> heading changes than a power boater but still the human is the backup.
>>> 
>>> Most autopilots don't directly follow GPS, they use GPS to determine a
>>> heading, follow it then use GPS to detect drift and re-compute the
>>> heading.
>>>  the heading would be held by a compass sensor in a low-cost setup or in a
>>> larger setup a lazer ring gyro backed up by a compass. So a spoofed
>>> GPS
>>> would cause the autopilot to "think" there was a bigger crooswnd or
>>> current
>>> and make a bigger heading change.
>>> 
>>> I bet you could hijack a drone not a manned vehicle the pilot is trained
>>> to
>>> monitor the automation and he'd very quickly turn it off thinking it was
>>> broken.
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:
>>> 
 Prof. Humphry from Texas just reported being able to spoof GPS in the
 Med
 and take over the nav system of a luxury yacht. He's done this before
 with
 a drone in the US.
 
 LORAN as a backup, at least?
 
 -John
 
 ==
 
 
 
 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to
 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.
>>> 
>>> 
>>> 
>>> --
>>> 
>>> Chris Albertson
>>> Redondo Beach, California
>> 
>> 
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
> 
> 

Re: [time-nuts] GPS Spoofing

[Jim Sanford]

As a (former) Naval Officer, I will tell you that a competent mariner 
should always be using and cross-checking /all /sources -- GPS, radar, 
dead reconing, /looking out the window/, and even celestial in open ocean.


(I frequently had to remind my junior officers that nobody ever ran 
aground or collided with another ship from spending too much time 
looking out the window.  Way too easy to get their heads stuck in the 
radar or the GPS map.


73,
Jim
wb4...@amsat.org

On 7/27/2013 9:43 AM, Scott McGrath wrote:

Key here is how does the captain know that GPS is no longer providing an 
accurate fix?   You need 2 or more independent systems to cross check each 
other.

Sent from my iPhone

On Jul 27, 2013, at 12:21 AM, Jim Lux  wrote:


On 7/26/13 8:45 PM, J. Forster wrote:

I gather from the article, the GPS position was spoofed and the autopilot,
in bringing it back to where it was supposed to be, actually took it off
course.

There are places where a few hundred feet makes a big difference, viz. the
Costa Concordia.

IMO, this is a very convincing reason for something like LORAN.

I think it's a convincing argument for a captain who pays attention to the 
other navigation instruments and doesn't blindly follow the GPS.

It's also a convincing argument that shipboard automation/autopilot/autocontrol 
vendors need to make more sophisticated software (which I suspect they do, 
particularly on 200+ foot ships.. I would imagine that there are some aspects 
of this demo that are contrived.)  The ship making and driving business is 
pretty unregulated. It's all about what the owner of the ship is willing to pay 
(or what he needs to get liability insurance, if he wants).  There's nothing 
even remotely like DO-178 for shipboard stuff.

The folks doing stabilized oil rigs probably have sophisticated systems, but 
they're also using IMUs and other stuff. Ditto for high value things (oil 
tankers, warships).  Molasses tankers? They're probably lucky to have a 
functioning compass and some old charts.


I'm not sure, though, that looking at the big picture, whether your tax dollars 
are better spent on LORAN, or on some other precision navigation method or on 
making jam resistant GPS receivers (which do, in fact exist, and make use of 
things like direction of arrival of the signal..)

Note that a GPS system with 3 antennas (as is common in systems that use GPS to 
derive attitude/orientation) would be extremely difficult to spoof, and would 
be VERY inexpensive to implement.  Either the carrier phases and code phases 
are consistent for all the received signals or they're not.  A jamming signal 
coming from the wrong direction will not have the right direction of arrival 
relative to the platform orientation.  One wrong signal might be tolerable 
(multipath, etc.) but with a multi satellite fix, I suspect it would be hard to 
do it.

Sure, one could throw up N pseudolites on a bunch of UAVs, etc., but that's 
getting to be a bit noticeable.


For what it's worth, I don't know that LORAN has the performance to avoid a 
Costa Concordia type foul up (assuming they were crazy enough to do the near 
pass in the fog, so visual navigation didn't work)

I seem to recall that LORAN had 1/4 nmi kinds of accuracy.  it would get you to 
the channel or mouth of the harbor, but not get you into your berth. You might 
be familiar with the local propagation anomalies and get better accuracy with 
experience in your local waters.







-John

=




I boat?  The backup is a competent captain.  He'd see the compass heading
move and quickly disengage the autopilot.   I had a boat for years  I'd
notice a 5 degree change.  Mine was a sailboat so I'd be more sensitive to
heading changes than a power boater but still the human is the backup.

Most autopilots don't directly follow GPS, they use GPS to determine a
heading, follow it then use GPS to detect drift and re-compute the
heading.
  the heading would be held by a compass sensor in a low-cost setup or in a
larger setup a lazer ring gyro backed up by a compass. So a spoofed
GPS
would cause the autopilot to "think" there was a bigger crooswnd or
current
and make a bigger heading change.

I bet you could hijack a drone not a manned vehicle the pilot is trained
to
monitor the automation and he'd very quickly turn it off thinking it was
broken.






On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:


Prof. Humphry from Texas just reported being able to spoof GPS in the
Med
and take over the nav system of a luxury yacht. He's done this before
with
a drone in the US.

LORAN as a backup, at least?

-John

==



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



--

Chris Albertson
Redondo Beach, California


___
time-nuts mailing list -- time-nuts@febo.c

Re: [time-nuts] GPS Spoofing

[J. Forster]

People screw up. Period. The Costa Concordia, that Talgo train driver in
Spain, pilots fly into the ground as in San Francisco, just to name a few.

IMO, putting all one's eggs in the GPS basket is simply foolish,
especially when a continuous cross-check with an independant nav system
can be implemented, probably for lest cost than a dinner at the Captain's
Table.

I was a guest on the bridge of a ship as it went through the Straights of
Gibralter and the Captain was using RADAR, Peloris sights, and multiple
lookouts. Suspenders and a belt.

The modern supertankers and container ships probably don't do that. The
highly automated ships don't carry a lot of crew.

-John

=




> As a (former) Naval Officer, I will tell you that a competent mariner
> should always be using and cross-checking /all /sources -- GPS, radar,
> dead reconing, /looking out the window/, and even celestial in open ocean.
>
> (I frequently had to remind my junior officers that nobody ever ran
> aground or collided with another ship from spending too much time
> looking out the window.  Way too easy to get their heads stuck in the
> radar or the GPS map.
>
> 73,
> Jim
> wb4...@amsat.org
>
> On 7/27/2013 9:43 AM, Scott McGrath wrote:
>> Key here is how does the captain know that GPS is no longer providing an
>> accurate fix?   You need 2 or more independent systems to cross check
>> each other.
>>
>> Sent from my iPhone
>>
>> On Jul 27, 2013, at 12:21 AM, Jim Lux  wrote:
>>
>>> On 7/26/13 8:45 PM, J. Forster wrote:
 I gather from the article, the GPS position was spoofed and the
 autopilot,
 in bringing it back to where it was supposed to be, actually took it
 off
 course.

 There are places where a few hundred feet makes a big difference, viz.
 the
 Costa Concordia.

 IMO, this is a very convincing reason for something like LORAN.
>>> I think it's a convincing argument for a captain who pays attention to
>>> the other navigation instruments and doesn't blindly follow the GPS.
>>>
>>> It's also a convincing argument that shipboard
>>> automation/autopilot/autocontrol vendors need to make more
>>> sophisticated software (which I suspect they do, particularly on 200+
>>> foot ships.. I would imagine that there are some aspects of this demo
>>> that are contrived.)  The ship making and driving business is pretty
>>> unregulated. It's all about what the owner of the ship is willing to
>>> pay (or what he needs to get liability insurance, if he wants).
>>> There's nothing even remotely like DO-178 for shipboard stuff.
>>>
>>> The folks doing stabilized oil rigs probably have sophisticated
>>> systems, but they're also using IMUs and other stuff. Ditto for high
>>> value things (oil tankers, warships).  Molasses tankers? They're
>>> probably lucky to have a functioning compass and some old charts.
>>>
>>>
>>> I'm not sure, though, that looking at the big picture, whether your tax
>>> dollars are better spent on LORAN, or on some other precision
>>> navigation method or on making jam resistant GPS receivers (which do,
>>> in fact exist, and make use of things like direction of arrival of the
>>> signal..)
>>>
>>> Note that a GPS system with 3 antennas (as is common in systems that
>>> use GPS to derive attitude/orientation) would be extremely difficult to
>>> spoof, and would be VERY inexpensive to implement.  Either the carrier
>>> phases and code phases are consistent for all the received signals or
>>> they're not.  A jamming signal coming from the wrong direction will not
>>> have the right direction of arrival relative to the platform
>>> orientation.  One wrong signal might be tolerable (multipath, etc.) but
>>> with a multi satellite fix, I suspect it would be hard to do it.
>>>
>>> Sure, one could throw up N pseudolites on a bunch of UAVs, etc., but
>>> that's getting to be a bit noticeable.
>>>
>>>
>>> For what it's worth, I don't know that LORAN has the performance to
>>> avoid a Costa Concordia type foul up (assuming they were crazy enough
>>> to do the near pass in the fog, so visual navigation didn't work)
>>>
>>> I seem to recall that LORAN had 1/4 nmi kinds of accuracy.  it would
>>> get you to the channel or mouth of the harbor, but not get you into
>>> your berth. You might be familiar with the local propagation anomalies
>>> and get better accuracy with experience in your local waters.
>>>
>>>
>>>
>>>
>>>
>>>
 -John

 =



> I boat?  The backup is a competent captain.  He'd see the compass
> heading
> move and quickly disengage the autopilot.   I had a boat for years
> I'd
> notice a 5 degree change.  Mine was a sailboat so I'd be more
> sensitive to
> heading changes than a power boater but still the human is the
> backup.
>
> Most autopilots don't directly follow GPS, they use GPS to determine
> a
> heading, follow it then use GPS to detect drift and re-compute the
> heading.

Re: [time-nuts] GPS Spoofing

[Michael Perrett]

I have seen a lot of differing opinions on GPS Spoofing and using back up
systems on this thread. Most pretty good, but a couple off the mark a bit.

Here are a couple of comments on GPS Spoofing.

   - There are anti-spoofing GPS receivers available - to "authorized"
   users. Typically DOD. Most, if not all, military receivers utilize the
   encrypted "P-Code", while civilians must use the more vulnerable clear text
   "C/A code". The P-Code signals are very difficult to spoof unless you have
   a-pirori knowledge. The newer satellites (GPS III) will have an even more
   robust AS methodology.
  - Note: beware of P-Code, or Military, receivers available on eBay.
  They are useless without the encryption keys distributed by the US
  Government.
  - In the (near?) future there will be four civilian GPS Signals: "The
   government is in the process of fielding three new signals designed for
   civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or
   C/A at L1, will continue broadcasting in the future, for a total of four
   civil GPS signals. Users must upgrade their equipment to benefit from the
   new signals". ref
   http://www.gps.gov/systems/gps/modernization/civilsignals/
   - Receivers utilizing the new civilian GPS frequencies can solve the GPS
   equations from more than one frequency and see if any one signal is being
   spoofed. The new civilian frequencies will be more spoof resistant.

Comments on using inertial measurement units (IMUs) to back up GPS.

   - Current IMUs with even a "good" drift rate of say, 1 degree per hour,
   available for around a few thousand dollars, will be off 60 nautical miles
   after an hour of uncorrected operation. That can be reduced by other sensor
   inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
   solution will eventually degrade to the accuracy of the external sensor. If
   my memory serves me for a really deep pocket navigator (having tens to
   hundreds of thousands of dollars, and a large amount of available mounting
   space) IMUs with drift rates of up to a thousand times less can be
   purchased (that's ,001 miles per hour, or around a couple of meters per
   hour), think submarines, etc.

Using a dual sensor navigation system (or timing system! ), such as
GPS/eLORAN, would obviously make the system so much more robust.

Michael / K7HIL

On Sat, Jul 27, 2013 at 6:43 AM, Scott McGrath  wrote:

> Key here is how does the captain know that GPS is no longer providing an
> accurate fix?   You need 2 or more independent systems to cross check each
> other.
>
> Sent from my iPhone
>
> On Jul 27, 2013, at 12:21 AM, Jim Lux  wrote:
>
> > On 7/26/13 8:45 PM, J. Forster wrote:
> >> I gather from the article, the GPS position was spoofed and the
> autopilot,
> >> in bringing it back to where it was supposed to be, actually took it off
> >> course.
> >>
> >> There are places where a few hundred feet makes a big difference, viz.
> the
> >> Costa Concordia.
> >>
> >> IMO, this is a very convincing reason for something like LORAN.
> >
> > I think it's a convincing argument for a captain who pays attention to
> the other navigation instruments and doesn't blindly follow the GPS.
> >
> > It's also a convincing argument that shipboard
> automation/autopilot/autocontrol vendors need to make more sophisticated
> software (which I suspect they do, particularly on 200+ foot ships.. I
> would imagine that there are some aspects of this demo that are contrived.)
>  The ship making and driving business is pretty unregulated. It's all about
> what the owner of the ship is willing to pay (or what he needs to get
> liability insurance, if he wants).  There's nothing even remotely like
> DO-178 for shipboard stuff.
> >
> > The folks doing stabilized oil rigs probably have sophisticated systems,
> but they're also using IMUs and other stuff. Ditto for high value things
> (oil tankers, warships).  Molasses tankers? They're probably lucky to have
> a functioning compass and some old charts.
> >
> >
> > I'm not sure, though, that looking at the big picture, whether your tax
> dollars are better spent on LORAN, or on some other precision navigation
> method or on making jam resistant GPS receivers (which do, in fact exist,
> and make use of things like direction of arrival of the signal..)
> >
> > Note that a GPS system with 3 antennas (as is common in systems that use
> GPS to derive attitude/orientation) would be extremely difficult to spoof,
> and would be VERY inexpensive to implement.  Either the carrier phases and
> code phases are consistent for all the received signals or they're not.  A
> jamming signal coming from the wrong direction will not have the right
> direction of arrival relative to the platform orientation.  One wrong
> signal might be tolerable (multipath, etc.) but with a multi satellite fix,
> I suspect it would be hard to do it.
> >
> > Sure, one could throw up N pseudolites on a bunch of UAVs, etc., but

Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Which is why the regulations (air or sea) *require*  you to be using at least 
two nav systems to check each other. If you are depending on only one system, 
your breaking the rules. It's not a matter of weather there are 100,000 systems 
available or not. It's a matter of weather they follow the rules. 

Bob

On Jul 27, 2013, at 9:43 AM, Scott McGrath  wrote:

> Key here is how does the captain know that GPS is no longer providing an 
> accurate fix?   You need 2 or more independent systems to cross check each 
> other.  
> 
> Sent from my iPhone
> 
> On Jul 27, 2013, at 12:21 AM, Jim Lux  wrote:
> 
>> On 7/26/13 8:45 PM, J. Forster wrote:
>>> I gather from the article, the GPS position was spoofed and the autopilot,
>>> in bringing it back to where it was supposed to be, actually took it off
>>> course.
>>> 
>>> There are places where a few hundred feet makes a big difference, viz. the
>>> Costa Concordia.
>>> 
>>> IMO, this is a very convincing reason for something like LORAN.
>> 
>> I think it's a convincing argument for a captain who pays attention to the 
>> other navigation instruments and doesn't blindly follow the GPS.
>> 
>> It's also a convincing argument that shipboard 
>> automation/autopilot/autocontrol vendors need to make more sophisticated 
>> software (which I suspect they do, particularly on 200+ foot ships.. I would 
>> imagine that there are some aspects of this demo that are contrived.)  The 
>> ship making and driving business is pretty unregulated. It's all about what 
>> the owner of the ship is willing to pay (or what he needs to get liability 
>> insurance, if he wants).  There's nothing even remotely like DO-178 for 
>> shipboard stuff.
>> 
>> The folks doing stabilized oil rigs probably have sophisticated systems, but 
>> they're also using IMUs and other stuff. Ditto for high value things (oil 
>> tankers, warships).  Molasses tankers? They're probably lucky to have a 
>> functioning compass and some old charts.
>> 
>> 
>> I'm not sure, though, that looking at the big picture, whether your tax 
>> dollars are better spent on LORAN, or on some other precision navigation 
>> method or on making jam resistant GPS receivers (which do, in fact exist, 
>> and make use of things like direction of arrival of the signal..)
>> 
>> Note that a GPS system with 3 antennas (as is common in systems that use GPS 
>> to derive attitude/orientation) would be extremely difficult to spoof, and 
>> would be VERY inexpensive to implement.  Either the carrier phases and code 
>> phases are consistent for all the received signals or they're not.  A 
>> jamming signal coming from the wrong direction will not have the right 
>> direction of arrival relative to the platform orientation.  One wrong signal 
>> might be tolerable (multipath, etc.) but with a multi satellite fix, I 
>> suspect it would be hard to do it.
>> 
>> Sure, one could throw up N pseudolites on a bunch of UAVs, etc., but that's 
>> getting to be a bit noticeable.
>> 
>> 
>> For what it's worth, I don't know that LORAN has the performance to avoid a 
>> Costa Concordia type foul up (assuming they were crazy enough to do the near 
>> pass in the fog, so visual navigation didn't work)
>> 
>> I seem to recall that LORAN had 1/4 nmi kinds of accuracy.  it would get you 
>> to the channel or mouth of the harbor, but not get you into your berth. You 
>> might be familiar with the local propagation anomalies and get better 
>> accuracy with experience in your local waters.
>> 
>> 
>> 
>> 
>> 
>> 
>>> 
>>> -John
>>> 
>>> =
>>> 
>>> 
>>> 
 I boat?  The backup is a competent captain.  He'd see the compass heading
 move and quickly disengage the autopilot.   I had a boat for years  I'd
 notice a 5 degree change.  Mine was a sailboat so I'd be more sensitive to
 heading changes than a power boater but still the human is the backup.
 
 Most autopilots don't directly follow GPS, they use GPS to determine a
 heading, follow it then use GPS to detect drift and re-compute the
 heading.
 the heading would be held by a compass sensor in a low-cost setup or in a
 larger setup a lazer ring gyro backed up by a compass. So a spoofed
 GPS
 would cause the autopilot to "think" there was a bigger crooswnd or
 current
 and make a bigger heading change.
 
 I bet you could hijack a drone not a manned vehicle the pilot is trained
 to
 monitor the automation and he'd very quickly turn it off thinking it was
 broken.
 
 
 
 
 
 
 On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:
 
> Prof. Humphry from Texas just reported being able to spoof GPS in the
> Med
> and take over the nav system of a luxury yacht. He's done this before
> with
> a drone in the US.
> 
> LORAN as a backup, at least?
> 
> -John
> 
> ==
> 
> 
> 
> __

Re: [time-nuts] GPS Spoofing

[Chris Albertson]

What is the failure rate?   The number of failures does not matter unless
we know the total number of attempts.

Do 1% of the ships that leave a harbor to become involved in an accident or
is  it more like one in one ten million?

I'd bet there are tens of thousands of cases of GPS failures where the user
said to himself "darn, it's broken" turned the thing off and went on his
way.




On Sat, Jul 27, 2013 at 1:51 AM, Robert Atkinson wrote:

> It seems you can't rely on the human backup. The UK Marine accident
> Investigation Branch Has recorded numerous accidents due to poor lookout.
> See
> http://www.maib.gov.uk/cms_resources.cfm?file=/KarinSchepersReportWeb.pdf
> http://www.maib.gov.uk/cms_resources.cfm?file=/CoastalIsle.pdf
> http://www.maib.gov.uk/cms_resources.cfm?file=/Beaumont.pdf
> http://www.maib.gov.uk/cms_resources.cfm?file=/Seagate_ReportWeb.pdf
> for recent examplesThe other problem is that AIS, a significant
> anti-collision aid, relies on GPS and is susceptable to spoofing.
>
> Robert G8RPI.
>
>
> 
>  From: Chris Albertson 
> To: j...@quikus.com; Discussion of precise time and frequency measurement
> 
> Sent: Saturday, 27 July 2013, 4:18
> Subject: Re: [time-nuts] GPS Spoofing
>
>
> I boat?  The backup is a competent captain.  He'd see the compass heading
> move and quickly disengage the autopilot.   I had a boat for years  I'd
> notice a 5 degree change.  Mine was a sailboat so I'd be more sensitive to
> heading changes than a power boater but still the human is the backup.
>
> Most autopilots don't directly follow GPS, they use GPS to determine a
> heading, follow it then use GPS to detect drift and re-compute the heading.
> the heading would be held by a compass sensor in a low-cost setup or in a
> larger setup a lazer ring gyro backed up by a compass. So a spoofed GPS
> would cause the autopilot to "think" there was a bigger crooswnd or current
> and make a bigger heading change.
>
> I bet you could hijack a drone not a manned vehicle the pilot is trained to
> monitor the automation and he'd very quickly turn it off thinking it was
> broken.
>
>
>
>
>
>
> On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:
>
> > Prof. Humphry from Texas just reported being able to spoof GPS in the Med
> > and take over the nav system of a luxury yacht. He's done this before
> with
> > a drone in the US.
> >
> > LORAN as a backup, at least?
> >
> > -John
> >
> > ==
> >
> >
> >
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
>
>
>
> --
>
> Chris Albertson
> Redondo Beach, California
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> ___
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> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 

Chris Albertson
Redondo Beach, California
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and follow the instructions there.

Re: [time-nuts] GPS Spoofing

[J. Forster]

The failure rate does not matter a whole lot, if you or a loved one are
killed or injured.

How much comfort is it to a victim, if 1 person, or 5 million people,
survived ?

Failure rates only really matter to actuaries and insurance companies.

-John

=



> What is the failure rate?   The number of failures does not matter unless
> we know the total number of attempts.
>
> Do 1% of the ships that leave a harbor to become involved in an accident
> or
> is  it more like one in one ten million?
>
> I'd bet there are tens of thousands of cases of GPS failures where the
> user
> said to himself "darn, it's broken" turned the thing off and went on his
> way.
>
>
>
>
> On Sat, Jul 27, 2013 at 1:51 AM, Robert Atkinson
> wrote:
>
>> It seems you can't rely on the human backup. The UK Marine accident
>> Investigation Branch Has recorded numerous accidents due to poor
>> lookout.
>> See
>> http://www.maib.gov.uk/cms_resources.cfm?file=/KarinSchepersReportWeb.pdf
>> http://www.maib.gov.uk/cms_resources.cfm?file=/CoastalIsle.pdf
>> http://www.maib.gov.uk/cms_resources.cfm?file=/Beaumont.pdf
>> http://www.maib.gov.uk/cms_resources.cfm?file=/Seagate_ReportWeb.pdf
>> for recent examplesThe other problem is that AIS, a significant
>> anti-collision aid, relies on GPS and is susceptable to spoofing.
>>
>> Robert G8RPI.
>>
>>
>> ____
>>  From: Chris Albertson 
>> To: j...@quikus.com; Discussion of precise time and frequency
>> measurement
>> 
>> Sent: Saturday, 27 July 2013, 4:18
>> Subject: Re: [time-nuts] GPS Spoofing
>>
>>
>> I boat?  The backup is a competent captain.  He'd see the compass
>> heading
>> move and quickly disengage the autopilot.   I had a boat for years  I'd
>> notice a 5 degree change.  Mine was a sailboat so I'd be more sensitive
>> to
>> heading changes than a power boater but still the human is the backup.
>>
>> Most autopilots don't directly follow GPS, they use GPS to determine a
>> heading, follow it then use GPS to detect drift and re-compute the
>> heading.
>> the heading would be held by a compass sensor in a low-cost setup or in
>> a
>> larger setup a lazer ring gyro backed up by a compass. So a spoofed
>> GPS
>> would cause the autopilot to "think" there was a bigger crooswnd or
>> current
>> and make a bigger heading change.
>>
>> I bet you could hijack a drone not a manned vehicle the pilot is trained
>> to
>> monitor the automation and he'd very quickly turn it off thinking it was
>> broken.
>>
>>
>>
>>
>>
>>
>> On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:
>>
>> > Prof. Humphry from Texas just reported being able to spoof GPS in the
>> Med
>> > and take over the nav system of a luxury yacht. He's done this before
>> with
>> > a drone in the US.
>> >
>> > LORAN as a backup, at least?
>> >
>> > -John
>> >
>> > ==
>> >
>> >
>> >
>> > ___
>> > time-nuts mailing list -- time-nuts@febo.com
>> > To unsubscribe, go to
>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > and follow the instructions there.
>> >
>>
>>
>>
>> --
>>
>> Chris Albertson
>> Redondo Beach, California
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
>
>
> --
>
> Chris Albertson
> Redondo Beach, California
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>


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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Also to the same point - which system is more reliable? You can ask the people 
who now use GPS how it compares in failure rate to what they used before. I 
know what kind of answers I get when I ask those questions ….

Bob

On Jul 27, 2013, at 1:10 PM, Chris Albertson  wrote:

> What is the failure rate?   The number of failures does not matter unless
> we know the total number of attempts.
> 
> Do 1% of the ships that leave a harbor to become involved in an accident or
> is  it more like one in one ten million?
> 
> I'd bet there are tens of thousands of cases of GPS failures where the user
> said to himself "darn, it's broken" turned the thing off and went on his
> way.
> 
> 
> 
> 
> On Sat, Jul 27, 2013 at 1:51 AM, Robert Atkinson 
> wrote:
> 
>> It seems you can't rely on the human backup. The UK Marine accident
>> Investigation Branch Has recorded numerous accidents due to poor lookout.
>> See
>> http://www.maib.gov.uk/cms_resources.cfm?file=/KarinSchepersReportWeb.pdf
>> http://www.maib.gov.uk/cms_resources.cfm?file=/CoastalIsle.pdf
>> http://www.maib.gov.uk/cms_resources.cfm?file=/Beaumont.pdf
>> http://www.maib.gov.uk/cms_resources.cfm?file=/Seagate_ReportWeb.pdf
>> for recent examplesThe other problem is that AIS, a significant
>> anti-collision aid, relies on GPS and is susceptable to spoofing.
>> 
>> Robert G8RPI.
>> 
>> 
>> 
>> From: Chris Albertson 
>> To: j...@quikus.com; Discussion of precise time and frequency measurement
>> 
>> Sent: Saturday, 27 July 2013, 4:18
>> Subject: Re: [time-nuts] GPS Spoofing
>> 
>> 
>> I boat?  The backup is a competent captain.  He'd see the compass heading
>> move and quickly disengage the autopilot.   I had a boat for years  I'd
>> notice a 5 degree change.  Mine was a sailboat so I'd be more sensitive to
>> heading changes than a power boater but still the human is the backup.
>> 
>> Most autopilots don't directly follow GPS, they use GPS to determine a
>> heading, follow it then use GPS to detect drift and re-compute the heading.
>> the heading would be held by a compass sensor in a low-cost setup or in a
>> larger setup a lazer ring gyro backed up by a compass. So a spoofed GPS
>> would cause the autopilot to "think" there was a bigger crooswnd or current
>> and make a bigger heading change.
>> 
>> I bet you could hijack a drone not a manned vehicle the pilot is trained to
>> monitor the automation and he'd very quickly turn it off thinking it was
>> broken.
>> 
>> 
>> 
>> 
>> 
>> 
>> On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:
>> 
>>> Prof. Humphry from Texas just reported being able to spoof GPS in the Med
>>> and take over the nav system of a luxury yacht. He's done this before
>> with
>>> a drone in the US.
>>> 
>>> LORAN as a backup, at least?
>>> 
>>> -John
>>> 
>>> ==
>>> 
>>> 
>>> 
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> 
>> 
>> 
>> 
>> --
>> 
>> Chris Albertson
>> Redondo Beach, California
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
> 
> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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Re: [time-nuts] GPS Spoofing

[Tom Holmes]

And engineers.

Tom Holmes, N8ZM
Tipp City, OH
EM79


> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On 
> Behalf Of J.
> Forster
> Sent: Saturday, July 27, 2013 1:21 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] GPS Spoofing
> 
> The failure rate does not matter a whole lot, if you or a loved one are 
> killed or
injured.
> 
> How much comfort is it to a victim, if 1 person, or 5 million people, 
> survived ?
> 
> Failure rates only really matter to actuaries and insurance companies.
> 
> -John
> 
> =
> 
> 
> 
> > What is the failure rate?   The number of failures does not matter unless
> > we know the total number of attempts.
> >
> > Do 1% of the ships that leave a harbor to become involved in an
> > accident or is  it more like one in one ten million?
> >
> > I'd bet there are tens of thousands of cases of GPS failures where the
> > user said to himself "darn, it's broken" turned the thing off and went
> > on his way.
> >
> >
> >
> >
> > On Sat, Jul 27, 2013 at 1:51 AM, Robert Atkinson
> > wrote:
> >
> >> It seems you can't rely on the human backup. The UK Marine accident
> >> Investigation Branch Has recorded numerous accidents due to poor
> >> lookout.
> >> See
> >> http://www.maib.gov.uk/cms_resources.cfm?file=/KarinSchepersReportWeb
> >> .pdf http://www.maib.gov.uk/cms_resources.cfm?file=/CoastalIsle.pdf
> >> http://www.maib.gov.uk/cms_resources.cfm?file=/Beaumont.pdf
> >> http://www.maib.gov.uk/cms_resources.cfm?file=/Seagate_ReportWeb.pdf
> >> for recent examplesThe other problem is that AIS, a significant
> >> anti-collision aid, relies on GPS and is susceptable to spoofing.
> >>
> >> Robert G8RPI.
> >>
> >>
> >> 
> >>  From: Chris Albertson 
> >> To: j...@quikus.com; Discussion of precise time and frequency
> >> measurement 
> >> Sent: Saturday, 27 July 2013, 4:18
> >> Subject: Re: [time-nuts] GPS Spoofing
> >>
> >>
> >> I boat?  The backup is a competent captain.  He'd see the compass
> >> heading
> >> move and quickly disengage the autopilot.   I had a boat for years  I'd
> >> notice a 5 degree change.  Mine was a sailboat so I'd be more
> >> sensitive to heading changes than a power boater but still the human
> >> is the backup.
> >>
> >> Most autopilots don't directly follow GPS, they use GPS to determine
> >> a heading, follow it then use GPS to detect drift and re-compute the
> >> heading.
> >> the heading would be held by a compass sensor in a low-cost setup or
> >> in a
> >> larger setup a lazer ring gyro backed up by a compass. So a spoofed
> >> GPS
> >> would cause the autopilot to "think" there was a bigger crooswnd or
> >> current and make a bigger heading change.
> >>
> >> I bet you could hijack a drone not a manned vehicle the pilot is
> >> trained to monitor the automation and he'd very quickly turn it off
> >> thinking it was broken.
> >>
> >>
> >>
> >>
> >>
> >>
> >> On Fri, Jul 26, 2013 at 8:41 AM, J. Forster  wrote:
> >>
> >> > Prof. Humphry from Texas just reported being able to spoof GPS in
> >> > the
> >> Med
> >> > and take over the nav system of a luxury yacht. He's done this
> >> > before
> >> with
> >> > a drone in the US.
> >> >
> >> > LORAN as a backup, at least?
> >> >
> >> > -John
> >> >
> >> > ==
> >> >
> >> >
> >> >
> >> > ___
> >> > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
> >> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> > and follow the instructions there.
> >> >
> >>
> >>
> >>
> >> --
> >>
> >> Chris Albertson
> >> Redondo Beach, California
> >> ___
> >> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >> ___
> >> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >>
> >
> >
> >
> > --
> >
> > Chris Albertson
> > Redondo Beach, California
> > ___
> > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
> >
> 
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-
> bin/mailman/listinfo/time-nuts
> and follow the instructions there.

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Re: [time-nuts] GPS Spoofing

[Scott McGrath]

Key

Problem with GPS is its easy to spoof on one level and have a complete denial 
of service on the other.   Out in California a while back a malfunctioning TV 
distribution amplifier jammed a major harbor and surrounding almost 25 sq miles 
affected all because of a 49.95 TV amp had a problem.  The military receivers 
had the same problem

LORAN is virtually jam proof unless you have a very powerful transmitter

Sent from my iPhone

On Jul 27, 2013, at 11:17 AM, Michael Perrett  wrote:

> I have seen a lot of differing opinions on GPS Spoofing and using back up
> systems on this thread. Most pretty good, but a couple off the mark a bit.
> 
> Here are a couple of comments on GPS Spoofing.
> 
>   - There are anti-spoofing GPS receivers available - to "authorized"
>   users. Typically DOD. Most, if not all, military receivers utilize the
>   encrypted "P-Code", while civilians must use the more vulnerable clear text
>   "C/A code". The P-Code signals are very difficult to spoof unless you have
>   a-pirori knowledge. The newer satellites (GPS III) will have an even more
>   robust AS methodology.
>  - Note: beware of P-Code, or Military, receivers available on eBay.
>  They are useless without the encryption keys distributed by the US
>  Government.
>  - In the (near?) future there will be four civilian GPS Signals: "The
>   government is in the process of fielding three new signals designed for
>   civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or
>   C/A at L1, will continue broadcasting in the future, for a total of four
>   civil GPS signals. Users must upgrade their equipment to benefit from the
>   new signals". ref
>   http://www.gps.gov/systems/gps/modernization/civilsignals/
>   - Receivers utilizing the new civilian GPS frequencies can solve the GPS
>   equations from more than one frequency and see if any one signal is being
>   spoofed. The new civilian frequencies will be more spoof resistant.
> 
> Comments on using inertial measurement units (IMUs) to back up GPS.
> 
>   - Current IMUs with even a "good" drift rate of say, 1 degree per hour,
>   available for around a few thousand dollars, will be off 60 nautical miles
>   after an hour of uncorrected operation. That can be reduced by other sensor
>   inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
>   solution will eventually degrade to the accuracy of the external sensor. If
>   my memory serves me for a really deep pocket navigator (having tens to
>   hundreds of thousands of dollars, and a large amount of available mounting
>   space) IMUs with drift rates of up to a thousand times less can be
>   purchased (that's ,001 miles per hour, or around a couple of meters per
>   hour), think submarines, etc.
> 
> Using a dual sensor navigation system (or timing system! ), such as
> GPS/eLORAN, would obviously make the system so much more robust.
> 
> Michael / K7HIL
> 
> On Sat, Jul 27, 2013 at 6:43 AM, Scott McGrath  wrote:
> 
>> Key here is how does the captain know that GPS is no longer providing an
>> accurate fix?   You need 2 or more independent systems to cross check each
>> other.
>> 
>> Sent from my iPhone
>> 
>> On Jul 27, 2013, at 12:21 AM, Jim Lux  wrote:
>> 
>>> On 7/26/13 8:45 PM, J. Forster wrote:
 I gather from the article, the GPS position was spoofed and the
>> autopilot,
 in bringing it back to where it was supposed to be, actually took it off
 course.
 
 There are places where a few hundred feet makes a big difference, viz.
>> the
 Costa Concordia.
 
 IMO, this is a very convincing reason for something like LORAN.
>>> 
>>> I think it's a convincing argument for a captain who pays attention to
>> the other navigation instruments and doesn't blindly follow the GPS.
>>> 
>>> It's also a convincing argument that shipboard
>> automation/autopilot/autocontrol vendors need to make more sophisticated
>> software (which I suspect they do, particularly on 200+ foot ships.. I
>> would imagine that there are some aspects of this demo that are contrived.)
>> The ship making and driving business is pretty unregulated. It's all about
>> what the owner of the ship is willing to pay (or what he needs to get
>> liability insurance, if he wants).  There's nothing even remotely like
>> DO-178 for shipboard stuff.
>>> 
>>> The folks doing stabilized oil rigs probably have sophisticated systems,
>> but they're also using IMUs and other stuff. Ditto for high value things
>> (oil tankers, warships).  Molasses tankers? They're probably lucky to have
>> a functioning compass and some old charts.
>>> 
>>> 
>>> I'm not sure, though, that looking at the big picture, whether your tax
>> dollars are better spent on LORAN, or on some other precision navigation
>> method or on making jam resistant GPS receivers (which do, in fact exist,
>> and make use of things like direction of arrival of the signal..)
>>> 
>>> Note that a GPS system with 3 antennas (as is common

Re: [time-nuts] GPS Spoofing

[J. Forster]

When Cape Cod LORAN was functional, I could easily see the pulses with a
few turn coil maybe a foot in diameter, roughly resonated, and a scope.

-John

==



> Key
>
> Problem with GPS is its easy to spoof on one level and have a complete
> denial of service on the other.   Out in California a while back a
> malfunctioning TV distribution amplifier jammed a major harbor and
> surrounding almost 25 sq miles affected all because of a 49.95 TV amp had
> a problem.  The military receivers had the same problem
>
> LORAN is virtually jam proof unless you have a very powerful transmitter
>
> Sent from my iPhone
>
> On Jul 27, 2013, at 11:17 AM, Michael Perrett  wrote:
>
>> I have seen a lot of differing opinions on GPS Spoofing and using back
>> up
>> systems on this thread. Most pretty good, but a couple off the mark a
>> bit.
>>
>> Here are a couple of comments on GPS Spoofing.
>>
>>   - There are anti-spoofing GPS receivers available - to "authorized"
>>   users. Typically DOD. Most, if not all, military receivers utilize the
>>   encrypted "P-Code", while civilians must use the more vulnerable clear
>> text
>>   "C/A code". The P-Code signals are very difficult to spoof unless you
>> have
>>   a-pirori knowledge. The newer satellites (GPS III) will have an even
>> more
>>   robust AS methodology.
>>  - Note: beware of P-Code, or Military, receivers available on eBay.
>>  They are useless without the encryption keys distributed by the US
>>  Government.
>>  - In the (near?) future there will be four civilian GPS Signals:
>> "The
>>   government is in the process of fielding three new signals designed
>> for
>>   civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A
>> or
>>   C/A at L1, will continue broadcasting in the future, for a total of
>> four
>>   civil GPS signals. Users must upgrade their equipment to benefit from
>> the
>>   new signals". ref
>>   http://www.gps.gov/systems/gps/modernization/civilsignals/
>>   - Receivers utilizing the new civilian GPS frequencies can solve the
>> GPS
>>   equations from more than one frequency and see if any one signal is
>> being
>>   spoofed. The new civilian frequencies will be more spoof resistant.
>>
>> Comments on using inertial measurement units (IMUs) to back up GPS.
>>
>>   - Current IMUs with even a "good" drift rate of say, 1 degree per
>> hour,
>>   available for around a few thousand dollars, will be off 60 nautical
>> miles
>>   after an hour of uncorrected operation. That can be reduced by other
>> sensor
>>   inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
>>   solution will eventually degrade to the accuracy of the external
>> sensor. If
>>   my memory serves me for a really deep pocket navigator (having tens to
>>   hundreds of thousands of dollars, and a large amount of available
>> mounting
>>   space) IMUs with drift rates of up to a thousand times less can be
>>   purchased (that's ,001 miles per hour, or around a couple of meters
>> per
>>   hour), think submarines, etc.
>>
>> Using a dual sensor navigation system (or timing system! ), such as
>> GPS/eLORAN, would obviously make the system so much more robust.
>>
>> Michael / K7HIL
>>
>> On Sat, Jul 27, 2013 at 6:43 AM, Scott McGrath 
>> wrote:
>>
>>> Key here is how does the captain know that GPS is no longer providing
>>> an
>>> accurate fix?   You need 2 or more independent systems to cross check
>>> each
>>> other.
>>>
>>> Sent from my iPhone
>>>
>>> On Jul 27, 2013, at 12:21 AM, Jim Lux  wrote:
>>>
 On 7/26/13 8:45 PM, J. Forster wrote:
> I gather from the article, the GPS position was spoofed and the
>>> autopilot,
> in bringing it back to where it was supposed to be, actually took it
> off
> course.
>
> There are places where a few hundred feet makes a big difference,
> viz.
>>> the
> Costa Concordia.
>
> IMO, this is a very convincing reason for something like LORAN.

 I think it's a convincing argument for a captain who pays attention to
>>> the other navigation instruments and doesn't blindly follow the GPS.

 It's also a convincing argument that shipboard
>>> automation/autopilot/autocontrol vendors need to make more
>>> sophisticated
>>> software (which I suspect they do, particularly on 200+ foot ships.. I
>>> would imagine that there are some aspects of this demo that are
>>> contrived.)
>>> The ship making and driving business is pretty unregulated. It's all
>>> about
>>> what the owner of the ship is willing to pay (or what he needs to get
>>> liability insurance, if he wants).  There's nothing even remotely like
>>> DO-178 for shipboard stuff.

 The folks doing stabilized oil rigs probably have sophisticated
 systems,
>>> but they're also using IMUs and other stuff. Ditto for high value
>>> things
>>> (oil tankers, warships).  Molasses tankers? They're probably lucky to
>>> have
>>> a functioning compass and some old charts.


 I'm n

Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Loran can / could easily be jammed over a limited area, just like GPS. Nothing 
crazy large or expensive would be required. The same sort of "malfunctioning 
this or that" took out Loran from time to time over harbor sized areas. Loran 
had so many issues with dropping out, that they simply were not worth talking 
about ….

Bob

On Jul 27, 2013, at 1:35 PM, Scott McGrath  wrote:

> Key
> 
> Problem with GPS is its easy to spoof on one level and have a complete denial 
> of service on the other.   Out in California a while back a malfunctioning TV 
> distribution amplifier jammed a major harbor and surrounding almost 25 sq 
> miles affected all because of a 49.95 TV amp had a problem.  The military 
> receivers had the same problem
> 
> LORAN is virtually jam proof unless you have a very powerful transmitter
> 
> Sent from my iPhone
> 
> On Jul 27, 2013, at 11:17 AM, Michael Perrett  wrote:
> 
>> I have seen a lot of differing opinions on GPS Spoofing and using back up
>> systems on this thread. Most pretty good, but a couple off the mark a bit.
>> 
>> Here are a couple of comments on GPS Spoofing.
>> 
>>  - There are anti-spoofing GPS receivers available - to "authorized"
>>  users. Typically DOD. Most, if not all, military receivers utilize the
>>  encrypted "P-Code", while civilians must use the more vulnerable clear text
>>  "C/A code". The P-Code signals are very difficult to spoof unless you have
>>  a-pirori knowledge. The newer satellites (GPS III) will have an even more
>>  robust AS methodology.
>> - Note: beware of P-Code, or Military, receivers available on eBay.
>> They are useless without the encryption keys distributed by the US
>> Government.
>> - In the (near?) future there will be four civilian GPS Signals: "The
>>  government is in the process of fielding three new signals designed for
>>  civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or
>>  C/A at L1, will continue broadcasting in the future, for a total of four
>>  civil GPS signals. Users must upgrade their equipment to benefit from the
>>  new signals". ref
>>  http://www.gps.gov/systems/gps/modernization/civilsignals/
>>  - Receivers utilizing the new civilian GPS frequencies can solve the GPS
>>  equations from more than one frequency and see if any one signal is being
>>  spoofed. The new civilian frequencies will be more spoof resistant.
>> 
>> Comments on using inertial measurement units (IMUs) to back up GPS.
>> 
>>  - Current IMUs with even a "good" drift rate of say, 1 degree per hour,
>>  available for around a few thousand dollars, will be off 60 nautical miles
>>  after an hour of uncorrected operation. That can be reduced by other sensor
>>  inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
>>  solution will eventually degrade to the accuracy of the external sensor. If
>>  my memory serves me for a really deep pocket navigator (having tens to
>>  hundreds of thousands of dollars, and a large amount of available mounting
>>  space) IMUs with drift rates of up to a thousand times less can be
>>  purchased (that's ,001 miles per hour, or around a couple of meters per
>>  hour), think submarines, etc.
>> 
>> Using a dual sensor navigation system (or timing system! ), such as
>> GPS/eLORAN, would obviously make the system so much more robust.
>> 
>> Michael / K7HIL
>> 
>> On Sat, Jul 27, 2013 at 6:43 AM, Scott McGrath  wrote:
>> 
>>> Key here is how does the captain know that GPS is no longer providing an
>>> accurate fix?   You need 2 or more independent systems to cross check each
>>> other.
>>> 
>>> Sent from my iPhone
>>> 
>>> On Jul 27, 2013, at 12:21 AM, Jim Lux  wrote:
>>> 
 On 7/26/13 8:45 PM, J. Forster wrote:
> I gather from the article, the GPS position was spoofed and the
>>> autopilot,
> in bringing it back to where it was supposed to be, actually took it off
> course.
> 
> There are places where a few hundred feet makes a big difference, viz.
>>> the
> Costa Concordia.
> 
> IMO, this is a very convincing reason for something like LORAN.
 
 I think it's a convincing argument for a captain who pays attention to
>>> the other navigation instruments and doesn't blindly follow the GPS.
 
 It's also a convincing argument that shipboard
>>> automation/autopilot/autocontrol vendors need to make more sophisticated
>>> software (which I suspect they do, particularly on 200+ foot ships.. I
>>> would imagine that there are some aspects of this demo that are contrived.)
>>> The ship making and driving business is pretty unregulated. It's all about
>>> what the owner of the ship is willing to pay (or what he needs to get
>>> liability insurance, if he wants).  There's nothing even remotely like
>>> DO-178 for shipboard stuff.
 
 The folks doing stabilized oil rigs probably have sophisticated systems,
>>> but they're also using IMUs and other stuff. Ditto for high value things
>>> (oil tankers, warships).

Re: [time-nuts] GPS Spoofing

[Scott McGrath]

LORAN was/is not perfect geographic features could and did limit reception   
However an effective jammer would need effective power in the hundred watt 
range and a efficient antenna system plus a connection to power grid or small 
Genset.  

Not amenable to easy concealment and fairly easy to DF using standard 
techniques especially since location of real station well known and fixed

An effective GPS jammer which can take out a few square miles is the size of a 
trade paperback and runs on batteries and costs under 50 bucks to build

Imagine a scenario where a few hundred of these are deployed with hostile 
intent.   

Military and Civillian systems are now useless due to nature of signal they are 
hard to DF

Sent from my iPhone

On Jul 27, 2013, at 2:09 PM, Bob Camp  wrote:

> Hi
> 
> Loran can / could easily be jammed over a limited area, just like GPS. 
> Nothing crazy large or expensive would be required. The same sort of 
> "malfunctioning this or that" took out Loran from time to time over harbor 
> sized areas. Loran had so many issues with dropping out, that they simply 
> were not worth talking about ….
> 
> Bob
> 
> On Jul 27, 2013, at 1:35 PM, Scott McGrath  wrote:
> 
>> Key
>> 
>> Problem with GPS is its easy to spoof on one level and have a complete 
>> denial of service on the other.   Out in California a while back a 
>> malfunctioning TV distribution amplifier jammed a major harbor and 
>> surrounding almost 25 sq miles affected all because of a 49.95 TV amp had a 
>> problem.  The military receivers had the same problem
>> 
>> LORAN is virtually jam proof unless you have a very powerful transmitter
>> 
>> Sent from my iPhone
>> 
>> On Jul 27, 2013, at 11:17 AM, Michael Perrett  wrote:
>> 
>>> I have seen a lot of differing opinions on GPS Spoofing and using back up
>>> systems on this thread. Most pretty good, but a couple off the mark a bit.
>>> 
>>> Here are a couple of comments on GPS Spoofing.
>>> 
>>> - There are anti-spoofing GPS receivers available - to "authorized"
>>> users. Typically DOD. Most, if not all, military receivers utilize the
>>> encrypted "P-Code", while civilians must use the more vulnerable clear text
>>> "C/A code". The P-Code signals are very difficult to spoof unless you have
>>> a-pirori knowledge. The newer satellites (GPS III) will have an even more
>>> robust AS methodology.
>>>- Note: beware of P-Code, or Military, receivers available on eBay.
>>>They are useless without the encryption keys distributed by the US
>>>Government.
>>>- In the (near?) future there will be four civilian GPS Signals: "The
>>> government is in the process of fielding three new signals designed for
>>> civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or
>>> C/A at L1, will continue broadcasting in the future, for a total of four
>>> civil GPS signals. Users must upgrade their equipment to benefit from the
>>> new signals". ref
>>> http://www.gps.gov/systems/gps/modernization/civilsignals/
>>> - Receivers utilizing the new civilian GPS frequencies can solve the GPS
>>> equations from more than one frequency and see if any one signal is being
>>> spoofed. The new civilian frequencies will be more spoof resistant.
>>> 
>>> Comments on using inertial measurement units (IMUs) to back up GPS.
>>> 
>>> - Current IMUs with even a "good" drift rate of say, 1 degree per hour,
>>> available for around a few thousand dollars, will be off 60 nautical miles
>>> after an hour of uncorrected operation. That can be reduced by other sensor
>>> inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
>>> solution will eventually degrade to the accuracy of the external sensor. If
>>> my memory serves me for a really deep pocket navigator (having tens to
>>> hundreds of thousands of dollars, and a large amount of available mounting
>>> space) IMUs with drift rates of up to a thousand times less can be
>>> purchased (that's ,001 miles per hour, or around a couple of meters per
>>> hour), think submarines, etc.
>>> 
>>> Using a dual sensor navigation system (or timing system! ), such as
>>> GPS/eLORAN, would obviously make the system so much more robust.
>>> 
>>> Michael / K7HIL
>>> 
>>> On Sat, Jul 27, 2013 at 6:43 AM, Scott McGrath  wrote:
>>> 
 Key here is how does the captain know that GPS is no longer providing an
 accurate fix?   You need 2 or more independent systems to cross check each
 other.
 
 Sent from my iPhone
 
 On Jul 27, 2013, at 12:21 AM, Jim Lux  wrote:
 
> On 7/26/13 8:45 PM, J. Forster wrote:
>> I gather from the article, the GPS position was spoofed and the
 autopilot,
>> in bringing it back to where it was supposed to be, actually took it off
>> course.
>> 
>> There are places where a few hundred feet makes a big difference, viz.
 the
>> Costa Concordia.
>> 
>> IMO, this is a very convincing reason for something like LORAN.
> 
> I think it's a co

Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

A Loran jammer would / could work with a *much* smaller antenna if a local area 
was the target. Power is easy at 100 KHz. Loran is no easier / harder to DF 
than GPS.

Bob

On Jul 27, 2013, at 3:37 PM, Scott McGrath  wrote:

> LORAN was/is not perfect geographic features could and did limit reception   
> However an effective jammer would need effective power in the hundred watt 
> range and a efficient antenna system plus a connection to power grid or small 
> Genset.  
> 
> Not amenable to easy concealment and fairly easy to DF using standard 
> techniques especially since location of real station well known and fixed
> 
> An effective GPS jammer which can take out a few square miles is the size of 
> a trade paperback and runs on batteries and costs under 50 bucks to build
> 
> Imagine a scenario where a few hundred of these are deployed with hostile 
> intent.   
> 
> Military and Civillian systems are now useless due to nature of signal they 
> are hard to DF
> 
> Sent from my iPhone
> 
> On Jul 27, 2013, at 2:09 PM, Bob Camp  wrote:
> 
>> Hi
>> 
>> Loran can / could easily be jammed over a limited area, just like GPS. 
>> Nothing crazy large or expensive would be required. The same sort of 
>> "malfunctioning this or that" took out Loran from time to time over harbor 
>> sized areas. Loran had so many issues with dropping out, that they simply 
>> were not worth talking about ….
>> 
>> Bob
>> 
>> On Jul 27, 2013, at 1:35 PM, Scott McGrath  wrote:
>> 
>>> Key
>>> 
>>> Problem with GPS is its easy to spoof on one level and have a complete 
>>> denial of service on the other.   Out in California a while back a 
>>> malfunctioning TV distribution amplifier jammed a major harbor and 
>>> surrounding almost 25 sq miles affected all because of a 49.95 TV amp had a 
>>> problem.  The military receivers had the same problem
>>> 
>>> LORAN is virtually jam proof unless you have a very powerful transmitter
>>> 
>>> Sent from my iPhone
>>> 
>>> On Jul 27, 2013, at 11:17 AM, Michael Perrett  wrote:
>>> 
 I have seen a lot of differing opinions on GPS Spoofing and using back up
 systems on this thread. Most pretty good, but a couple off the mark a bit.
 
 Here are a couple of comments on GPS Spoofing.
 
 - There are anti-spoofing GPS receivers available - to "authorized"
 users. Typically DOD. Most, if not all, military receivers utilize the
 encrypted "P-Code", while civilians must use the more vulnerable clear text
 "C/A code". The P-Code signals are very difficult to spoof unless you have
 a-pirori knowledge. The newer satellites (GPS III) will have an even more
 robust AS methodology.
   - Note: beware of P-Code, or Military, receivers available on eBay.
   They are useless without the encryption keys distributed by the US
   Government.
   - In the (near?) future there will be four civilian GPS Signals: "The
 government is in the process of fielding three new signals designed for
 civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or
 C/A at L1, will continue broadcasting in the future, for a total of four
 civil GPS signals. Users must upgrade their equipment to benefit from the
 new signals". ref
 http://www.gps.gov/systems/gps/modernization/civilsignals/
 - Receivers utilizing the new civilian GPS frequencies can solve the GPS
 equations from more than one frequency and see if any one signal is being
 spoofed. The new civilian frequencies will be more spoof resistant.
 
 Comments on using inertial measurement units (IMUs) to back up GPS.
 
 - Current IMUs with even a "good" drift rate of say, 1 degree per hour,
 available for around a few thousand dollars, will be off 60 nautical miles
 after an hour of uncorrected operation. That can be reduced by other sensor
 inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
 solution will eventually degrade to the accuracy of the external sensor. If
 my memory serves me for a really deep pocket navigator (having tens to
 hundreds of thousands of dollars, and a large amount of available mounting
 space) IMUs with drift rates of up to a thousand times less can be
 purchased (that's ,001 miles per hour, or around a couple of meters per
 hour), think submarines, etc.
 
 Using a dual sensor navigation system (or timing system! ), such as
 GPS/eLORAN, would obviously make the system so much more robust.
 
 Michael / K7HIL
 
 On Sat, Jul 27, 2013 at 6:43 AM, Scott McGrath  wrote:
 
> Key here is how does the captain know that GPS is no longer providing an
> accurate fix?   You need 2 or more independent systems to cross check each
> other.
> 
> Sent from my iPhone
> 
> On Jul 27, 2013, at 12:21 AM, Jim Lux  wrote:
> 
>> On 7/26/13 8:45 PM, J. Forster wrote:
>>> I gather from the article, the GPS position was spoofe

Re: [time-nuts] GPS Spoofing

[Scott McGrath]

Have you done any DF work with low chip rate spread spectrum signals down in 
the noise.It's not easy and you need to fft for the data

A high power pulse train lots easier to DF

Sent from my iPhone

On Jul 27, 2013, at 3:44 PM, Bob Camp  wrote:

> Hi
> 
> A Loran jammer would / could work with a *much* smaller antenna if a local 
> area was the target. Power is easy at 100 KHz. Loran is no easier / harder to 
> DF than GPS.
> 
> Bob
> 
> On Jul 27, 2013, at 3:37 PM, Scott McGrath  wrote:
> 
>> LORAN was/is not perfect geographic features could and did limit reception   
>> However an effective jammer would need effective power in the hundred watt 
>> range and a efficient antenna system plus a connection to power grid or 
>> small Genset.  
>> 
>> Not amenable to easy concealment and fairly easy to DF using standard 
>> techniques especially since location of real station well known and fixed
>> 
>> An effective GPS jammer which can take out a few square miles is the size of 
>> a trade paperback and runs on batteries and costs under 50 bucks to build
>> 
>> Imagine a scenario where a few hundred of these are deployed with hostile 
>> intent.   
>> 
>> Military and Civillian systems are now useless due to nature of signal they 
>> are hard to DF
>> 
>> Sent from my iPhone
>> 
>> On Jul 27, 2013, at 2:09 PM, Bob Camp  wrote:
>> 
>>> Hi
>>> 
>>> Loran can / could easily be jammed over a limited area, just like GPS. 
>>> Nothing crazy large or expensive would be required. The same sort of 
>>> "malfunctioning this or that" took out Loran from time to time over harbor 
>>> sized areas. Loran had so many issues with dropping out, that they simply 
>>> were not worth talking about ….
>>> 
>>> Bob
>>> 
>>> On Jul 27, 2013, at 1:35 PM, Scott McGrath  wrote:
>>> 
 Key
 
 Problem with GPS is its easy to spoof on one level and have a complete 
 denial of service on the other.   Out in California a while back a 
 malfunctioning TV distribution amplifier jammed a major harbor and 
 surrounding almost 25 sq miles affected all because of a 49.95 TV amp had 
 a problem.  The military receivers had the same problem
 
 LORAN is virtually jam proof unless you have a very powerful transmitter
 
 Sent from my iPhone
 
 On Jul 27, 2013, at 11:17 AM, Michael Perrett  wrote:
 
> I have seen a lot of differing opinions on GPS Spoofing and using back up
> systems on this thread. Most pretty good, but a couple off the mark a bit.
> 
> Here are a couple of comments on GPS Spoofing.
> 
> - There are anti-spoofing GPS receivers available - to "authorized"
> users. Typically DOD. Most, if not all, military receivers utilize the
> encrypted "P-Code", while civilians must use the more vulnerable clear 
> text
> "C/A code". The P-Code signals are very difficult to spoof unless you have
> a-pirori knowledge. The newer satellites (GPS III) will have an even more
> robust AS methodology.
>  - Note: beware of P-Code, or Military, receivers available on eBay.
>  They are useless without the encryption keys distributed by the US
>  Government.
>  - In the (near?) future there will be four civilian GPS Signals: "The
> government is in the process of fielding three new signals designed for
> civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or
> C/A at L1, will continue broadcasting in the future, for a total of four
> civil GPS signals. Users must upgrade their equipment to benefit from the
> new signals". ref
> http://www.gps.gov/systems/gps/modernization/civilsignals/
> - Receivers utilizing the new civilian GPS frequencies can solve the GPS
> equations from more than one frequency and see if any one signal is being
> spoofed. The new civilian frequencies will be more spoof resistant.
> 
> Comments on using inertial measurement units (IMUs) to back up GPS.
> 
> - Current IMUs with even a "good" drift rate of say, 1 degree per hour,
> available for around a few thousand dollars, will be off 60 nautical miles
> after an hour of uncorrected operation. That can be reduced by other 
> sensor
> inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
> solution will eventually degrade to the accuracy of the external sensor. 
> If
> my memory serves me for a really deep pocket navigator (having tens to
> hundreds of thousands of dollars, and a large amount of available mounting
> space) IMUs with drift rates of up to a thousand times less can be
> purchased (that's ,001 miles per hour, or around a couple of meters per
> hour), think submarines, etc.
> 
> Using a dual sensor navigation system (or timing system! ), such as
> GPS/eLORAN, would obviously make the system so much more robust.
> 
> Michael / K7HIL
> 
> On Sat, Jul 27, 2013 at 6:43 AM, Scott McGrath  
> wrote

Re: [time-nuts] GPS Spoofing

[stew...@g3ysx.org.uk]

LF is much easier to accurately DF than VHF and above due to multipath effects.

Stewart

Sent from my iPad

On 27 Jul 2013, at 21:44, Bob Camp  wrote:

> Hi
> 
> A Loran jammer would / could work with a *much* smaller antenna if a local 
> area was the target. Power is easy at 100 KHz. Loran is no easier / harder to 
> DF than GPS.
> 
> Bob
> 
> On Jul 27, 2013, at 3:37 PM, Scott McGrath  wrote:
> 
>> LORAN was/is not perfect geographic features could and did limit reception   
>> However an effective jammer would need effective power in the hundred watt 
>> range and a efficient antenna system plus a connection to power grid or 
>> small Genset.  
>> 
>> Not amenable to easy concealment and fairly easy to DF using standard 
>> techniques especially since location of real station well known and fixed
>> 
>> An effective GPS jammer which can take out a few square miles is the size of 
>> a trade paperback and runs on batteries and costs under 50 bucks to build
>> 
>> Imagine a scenario where a few hundred of these are deployed with hostile 
>> intent.   
>> 
>> Military and Civillian systems are now useless due to nature of signal they 
>> are hard to DF
>> 
>> Sent from my iPhone
>> 
>> On Jul 27, 2013, at 2:09 PM, Bob Camp  wrote:
>> 
>>> Hi
>>> 
>>> Loran can / could easily be jammed over a limited area, just like GPS. 
>>> Nothing crazy large or expensive would be required. The same sort of 
>>> "malfunctioning this or that" took out Loran from time to time over harbor 
>>> sized areas. Loran had so many issues with dropping out, that they simply 
>>> were not worth talking about ….
>>> 
>>> Bob
>>> 
>>> On Jul 27, 2013, at 1:35 PM, Scott McGrath  wrote:
>>> 
 Key
 
 Problem with GPS is its easy to spoof on one level and have a complete 
 denial of service on the other.   Out in California a while back a 
 malfunctioning TV distribution amplifier jammed a major harbor and 
 surrounding almost 25 sq miles affected all because of a 49.95 TV amp had 
 a problem.  The military receivers had the same problem
 
 LORAN is virtually jam proof unless you have a very powerful transmitter
 
 Sent from my iPhone
 
 On Jul 27, 2013, at 11:17 AM, Michael Perrett  wrote:
 
> I have seen a lot of differing opinions on GPS Spoofing and using back up
> systems on this thread. Most pretty good, but a couple off the mark a bit.
> 
> Here are a couple of comments on GPS Spoofing.
> 
> - There are anti-spoofing GPS receivers available - to "authorized"
> users. Typically DOD. Most, if not all, military receivers utilize the
> encrypted "P-Code", while civilians must use the more vulnerable clear 
> text
> "C/A code". The P-Code signals are very difficult to spoof unless you have
> a-pirori knowledge. The newer satellites (GPS III) will have an even more
> robust AS methodology.
>  - Note: beware of P-Code, or Military, receivers available on eBay.
>  They are useless without the encryption keys distributed by the US
>  Government.
>  - In the (near?) future there will be four civilian GPS Signals: "The
> government is in the process of fielding three new signals designed for
> civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or
> C/A at L1, will continue broadcasting in the future, for a total of four
> civil GPS signals. Users must upgrade their equipment to benefit from the
> new signals". ref
> http://www.gps.gov/systems/gps/modernization/civilsignals/
> - Receivers utilizing the new civilian GPS frequencies can solve the GPS
> equations from more than one frequency and see if any one signal is being
> spoofed. The new civilian frequencies will be more spoof resistant.
> 
> Comments on using inertial measurement units (IMUs) to back up GPS.
> 
> - Current IMUs with even a "good" drift rate of say, 1 degree per hour,
> available for around a few thousand dollars, will be off 60 nautical miles
> after an hour of uncorrected operation. That can be reduced by other 
> sensor
> inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
> solution will eventually degrade to the accuracy of the external sensor. 
> If
> my memory serves me for a really deep pocket navigator (having tens to
> hundreds of thousands of dollars, and a large amount of available mounting
> space) IMUs with drift rates of up to a thousand times less can be
> purchased (that's ,001 miles per hour, or around a couple of meters per
> hour), think submarines, etc.
> 
> Using a dual sensor navigation system (or timing system! ), such as
> GPS/eLORAN, would obviously make the system so much more robust.
> 
> Michael / K7HIL
> 
> On Sat, Jul 27, 2013 at 6:43 AM, Scott McGrath  
> wrote:
> 
>> Key here is how does the captain know that GPS is no longer providing an
>> acc

Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

One could say VHF is much easier to DF than LF due to the small antennas 
needed. Short wavelength makes the antenna for a phase based receiver easier to 
build.

Bob

On Jul 28, 2013, at 5:03 AM, stew...@g3ysx.org.uk  wrote:

> LF is much easier to accurately DF than VHF and above due to multipath 
> effects.
> 
> Stewart
> 
> Sent from my iPad
> 
> On 27 Jul 2013, at 21:44, Bob Camp  wrote:
> 
>> Hi
>> 
>> A Loran jammer would / could work with a *much* smaller antenna if a local 
>> area was the target. Power is easy at 100 KHz. Loran is no easier / harder 
>> to DF than GPS.
>> 
>> Bob
>> 
>> On Jul 27, 2013, at 3:37 PM, Scott McGrath  wrote:
>> 
>>> LORAN was/is not perfect geographic features could and did limit reception  
>>>  However an effective jammer would need effective power in the hundred watt 
>>> range and a efficient antenna system plus a connection to power grid or 
>>> small Genset.  
>>> 
>>> Not amenable to easy concealment and fairly easy to DF using standard 
>>> techniques especially since location of real station well known and fixed
>>> 
>>> An effective GPS jammer which can take out a few square miles is the size 
>>> of a trade paperback and runs on batteries and costs under 50 bucks to build
>>> 
>>> Imagine a scenario where a few hundred of these are deployed with hostile 
>>> intent.   
>>> 
>>> Military and Civillian systems are now useless due to nature of signal they 
>>> are hard to DF
>>> 
>>> Sent from my iPhone
>>> 
>>> On Jul 27, 2013, at 2:09 PM, Bob Camp  wrote:
>>> 
 Hi
 
 Loran can / could easily be jammed over a limited area, just like GPS. 
 Nothing crazy large or expensive would be required. The same sort of 
 "malfunctioning this or that" took out Loran from time to time over harbor 
 sized areas. Loran had so many issues with dropping out, that they simply 
 were not worth talking about ….
 
 Bob
 
 On Jul 27, 2013, at 1:35 PM, Scott McGrath  wrote:
 
> Key
> 
> Problem with GPS is its easy to spoof on one level and have a complete 
> denial of service on the other.   Out in California a while back a 
> malfunctioning TV distribution amplifier jammed a major harbor and 
> surrounding almost 25 sq miles affected all because of a 49.95 TV amp had 
> a problem.  The military receivers had the same problem
> 
> LORAN is virtually jam proof unless you have a very powerful transmitter
> 
> Sent from my iPhone
> 
> On Jul 27, 2013, at 11:17 AM, Michael Perrett  wrote:
> 
>> I have seen a lot of differing opinions on GPS Spoofing and using back up
>> systems on this thread. Most pretty good, but a couple off the mark a 
>> bit.
>> 
>> Here are a couple of comments on GPS Spoofing.
>> 
>> - There are anti-spoofing GPS receivers available - to "authorized"
>> users. Typically DOD. Most, if not all, military receivers utilize the
>> encrypted "P-Code", while civilians must use the more vulnerable clear 
>> text
>> "C/A code". The P-Code signals are very difficult to spoof unless you 
>> have
>> a-pirori knowledge. The newer satellites (GPS III) will have an even more
>> robust AS methodology.
>> - Note: beware of P-Code, or Military, receivers available on eBay.
>> They are useless without the encryption keys distributed by the US
>> Government.
>> - In the (near?) future there will be four civilian GPS Signals: "The
>> government is in the process of fielding three new signals designed for
>> civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or
>> C/A at L1, will continue broadcasting in the future, for a total of four
>> civil GPS signals. Users must upgrade their equipment to benefit from the
>> new signals". ref
>> http://www.gps.gov/systems/gps/modernization/civilsignals/
>> - Receivers utilizing the new civilian GPS frequencies can solve the GPS
>> equations from more than one frequency and see if any one signal is being
>> spoofed. The new civilian frequencies will be more spoof resistant.
>> 
>> Comments on using inertial measurement units (IMUs) to back up GPS.
>> 
>> - Current IMUs with even a "good" drift rate of say, 1 degree per hour,
>> available for around a few thousand dollars, will be off 60 nautical 
>> miles
>> after an hour of uncorrected operation. That can be reduced by other 
>> sensor
>> inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
>> solution will eventually degrade to the accuracy of the external sensor. 
>> If
>> my memory serves me for a really deep pocket navigator (having tens to
>> hundreds of thousands of dollars, and a large amount of available 
>> mounting
>> space) IMUs with drift rates of up to a thousand times less can be
>> purchased (that's ,001 miles per hour, or around a couple of meters per
>> hour), t

Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

With a small jammer, you have a fast change in power vs distance. That's true 
regardless of frequency. The way Loran works, the "jammer" would do better if 
it looked like the low power slave for the area, not the highest power station. 
In both the case of Loran and GPS, you would need to get close by survey rather 
than DF. For a small area of impact, that's pretty much the same in both cases.

Bob

On Jul 27, 2013, at 10:00 PM, Scott McGrath  wrote:

> Have you done any DF work with low chip rate spread spectrum signals down in 
> the noise.It's not easy and you need to fft for the data
> 
> A high power pulse train lots easier to DF
> 
> Sent from my iPhone
> 
> On Jul 27, 2013, at 3:44 PM, Bob Camp  wrote:
> 
>> Hi
>> 
>> A Loran jammer would / could work with a *much* smaller antenna if a local 
>> area was the target. Power is easy at 100 KHz. Loran is no easier / harder 
>> to DF than GPS.
>> 
>> Bob
>> 
>> On Jul 27, 2013, at 3:37 PM, Scott McGrath  wrote:
>> 
>>> LORAN was/is not perfect geographic features could and did limit reception  
>>>  However an effective jammer would need effective power in the hundred watt 
>>> range and a efficient antenna system plus a connection to power grid or 
>>> small Genset.  
>>> 
>>> Not amenable to easy concealment and fairly easy to DF using standard 
>>> techniques especially since location of real station well known and fixed
>>> 
>>> An effective GPS jammer which can take out a few square miles is the size 
>>> of a trade paperback and runs on batteries and costs under 50 bucks to build
>>> 
>>> Imagine a scenario where a few hundred of these are deployed with hostile 
>>> intent.   
>>> 
>>> Military and Civillian systems are now useless due to nature of signal they 
>>> are hard to DF
>>> 
>>> Sent from my iPhone
>>> 
>>> On Jul 27, 2013, at 2:09 PM, Bob Camp  wrote:
>>> 
 Hi
 
 Loran can / could easily be jammed over a limited area, just like GPS. 
 Nothing crazy large or expensive would be required. The same sort of 
 "malfunctioning this or that" took out Loran from time to time over harbor 
 sized areas. Loran had so many issues with dropping out, that they simply 
 were not worth talking about ….
 
 Bob
 
 On Jul 27, 2013, at 1:35 PM, Scott McGrath  wrote:
 
> Key
> 
> Problem with GPS is its easy to spoof on one level and have a complete 
> denial of service on the other.   Out in California a while back a 
> malfunctioning TV distribution amplifier jammed a major harbor and 
> surrounding almost 25 sq miles affected all because of a 49.95 TV amp had 
> a problem.  The military receivers had the same problem
> 
> LORAN is virtually jam proof unless you have a very powerful transmitter
> 
> Sent from my iPhone
> 
> On Jul 27, 2013, at 11:17 AM, Michael Perrett  wrote:
> 
>> I have seen a lot of differing opinions on GPS Spoofing and using back up
>> systems on this thread. Most pretty good, but a couple off the mark a 
>> bit.
>> 
>> Here are a couple of comments on GPS Spoofing.
>> 
>> - There are anti-spoofing GPS receivers available - to "authorized"
>> users. Typically DOD. Most, if not all, military receivers utilize the
>> encrypted "P-Code", while civilians must use the more vulnerable clear 
>> text
>> "C/A code". The P-Code signals are very difficult to spoof unless you 
>> have
>> a-pirori knowledge. The newer satellites (GPS III) will have an even more
>> robust AS methodology.
>> - Note: beware of P-Code, or Military, receivers available on eBay.
>> They are useless without the encryption keys distributed by the US
>> Government.
>> - In the (near?) future there will be four civilian GPS Signals: "The
>> government is in the process of fielding three new signals designed for
>> civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or
>> C/A at L1, will continue broadcasting in the future, for a total of four
>> civil GPS signals. Users must upgrade their equipment to benefit from the
>> new signals". ref
>> http://www.gps.gov/systems/gps/modernization/civilsignals/
>> - Receivers utilizing the new civilian GPS frequencies can solve the GPS
>> equations from more than one frequency and see if any one signal is being
>> spoofed. The new civilian frequencies will be more spoof resistant.
>> 
>> Comments on using inertial measurement units (IMUs) to back up GPS.
>> 
>> - Current IMUs with even a "good" drift rate of say, 1 degree per hour,
>> available for around a few thousand dollars, will be off 60 nautical 
>> miles
>> after an hour of uncorrected operation. That can be reduced by other 
>> sensor
>> inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
>> solution will eventually degrade to the accuracy of the external sensor. 
>> If
>>

Re: [time-nuts] GPS Spoofing

[Chris Albertson]

I think the GPS backups are called,

   - GLONASS 
   - Galileo
   - 
IRNSS
   - Compass 

They should all be up and running, especially the first two in 5 to 7 years.

But ALL radio navigation systems can be spoofed.   The ones you can't spoof
are



On Sun, Jul 28, 2013 at 2:03 AM, stew...@g3ysx.org.uk
wrote:

> LF is much easier to accurately DF than VHF and above due to multipath
> effects.
>
> Stewart
>
> Sent from my iPad
>
> On 27 Jul 2013, at 21:44, Bob Camp  wrote:
>
> > Hi
> >
> > A Loran jammer would / could work with a *much* smaller antenna if a
> local area was the target. Power is easy at 100 KHz. Loran is no easier /
> harder to DF than GPS.
> >
> > Bob
> >
> > On Jul 27, 2013, at 3:37 PM, Scott McGrath  wrote:
> >
> >> LORAN was/is not perfect geographic features could and did limit
> reception   However an effective jammer would need effective power in the
> hundred watt range and a efficient antenna system plus a connection to
> power grid or small Genset.
> >>
> >> Not amenable to easy concealment and fairly easy to DF using standard
> techniques especially since location of real station well known and fixed
> >>
> >> An effective GPS jammer which can take out a few square miles is the
> size of a trade paperback and runs on batteries and costs under 50 bucks to
> build
> >>
> >> Imagine a scenario where a few hundred of these are deployed with
> hostile intent.
> >>
> >> Military and Civillian systems are now useless due to nature of signal
> they are hard to DF
> >>
> >> Sent from my iPhone
> >>
> >> On Jul 27, 2013, at 2:09 PM, Bob Camp  wrote:
> >>
> >>> Hi
> >>>
> >>> Loran can / could easily be jammed over a limited area, just like GPS.
> Nothing crazy large or expensive would be required. The same sort of
> "malfunctioning this or that" took out Loran from time to time over harbor
> sized areas. Loran had so many issues with dropping out, that they simply
> were not worth talking about ….
> >>>
> >>> Bob
> >>>
> >>> On Jul 27, 2013, at 1:35 PM, Scott McGrath 
> wrote:
> >>>
>  Key
> 
>  Problem with GPS is its easy to spoof on one level and have a
> complete denial of service on the other.   Out in California a while back a
> malfunctioning TV distribution amplifier jammed a major harbor and
> surrounding almost 25 sq miles affected all because of a 49.95 TV amp had a
> problem.  The military receivers had the same problem
> 
>  LORAN is virtually jam proof unless you have a very powerful
> transmitter
> 
>  Sent from my iPhone
> 
>  On Jul 27, 2013, at 11:17 AM, Michael Perrett 
> wrote:
> 
> > I have seen a lot of differing opinions on GPS Spoofing and using
> back up
> > systems on this thread. Most pretty good, but a couple off the mark
> a bit.
> >
> > Here are a couple of comments on GPS Spoofing.
> >
> > - There are anti-spoofing GPS receivers available - to "authorized"
> > users. Typically DOD. Most, if not all, military receivers utilize
> the
> > encrypted "P-Code", while civilians must use the more vulnerable
> clear text
> > "C/A code". The P-Code signals are very difficult to spoof unless
> you have
> > a-pirori knowledge. The newer satellites (GPS III) will have an even
> more
> > robust AS methodology.
> >  - Note: beware of P-Code, or Military, receivers available on eBay.
> >  They are useless without the encryption keys distributed by the US
> >  Government.
> >  - In the (near?) future there will be four civilian GPS Signals:
> "The
> > government is in the process of fielding three new signals designed
> for
> > civilian use: L2C, L5, and L1C. The legacy civil signal, called L1
> C/A or
> > C/A at L1, will continue broadcasting in the future, for a total of
> four
> > civil GPS signals. Users must upgrade their equipment to benefit
> from the
> > new signals". ref
> > http://www.gps.gov/systems/gps/modernization/civilsignals/
> > - Receivers utilizing the new civilian GPS frequencies can solve the
> GPS
> > equations from more than one frequency and see if any one signal is
> being
> > spoofed. The new civilian frequencies will be more spoof resistant.
> >
> > Comments on using inertial measurement units (IMUs) to back up GPS.
> >
> > - Current IMUs with even a "good" drift rate of say, 1 degree per
> hour,
> > available for around a few thousand dollars, will be off 60 nautical
> miles
> > after an hour of uncorrected operation. That can be reduced by other
> sensor
> > inputs (GPS, LORAN, pit-log or what ever you have), but the
> navigation
> > solution will eventually degrade to the accuracy of the external
> sensor. If
> > my memory serves me for a rea

Re: [time-nuts] GPS Spoofing

[Poul-Henning Kamp]

In message 
, Chris Albertson writes:
>I think the GPS backups are called,

None of those are usable as backups for GPS, as they use the same
low-power Microwave signals as GPS.

>But ALL radio navigation systems can be spoofed.   The ones you can't spoof
>are

Loran-C.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
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Re: [time-nuts] GPS Spoofing

[Scott McGrath]

Yes it is and it can be done with simple loop stick antennas. Prior to wide use 
of loran ships would use LF beacons and DF receivers either manual automatic 

Periodically you will see shortwave receivers with a rotating antenna and a 
bearing ring you would find a bearing to a couple of beacon or broadcast 
station and calculate position based on triangulation 

Basically a radio version of a pelorus 


Sent from my iPhone

On Jul 28, 2013, at 5:03 AM, "stew...@g3ysx.org.uk"  
wrote:

> LF is much easier to accurately DF than VHF and above due to multipath 
> effects.
> 
> Stewart
> 
> Sent from my iPad
> 
> On 27 Jul 2013, at 21:44, Bob Camp  wrote:
> 
>> Hi
>> 
>> A Loran jammer would / could work with a *much* smaller antenna if a local 
>> area was the target. Power is easy at 100 KHz. Loran is no easier / harder 
>> to DF than GPS.
>> 
>> Bob
>> 
>> On Jul 27, 2013, at 3:37 PM, Scott McGrath  wrote:
>> 
>>> LORAN was/is not perfect geographic features could and did limit reception  
>>>  However an effective jammer would need effective power in the hundred watt 
>>> range and a efficient antenna system plus a connection to power grid or 
>>> small Genset.  
>>> 
>>> Not amenable to easy concealment and fairly easy to DF using standard 
>>> techniques especially since location of real station well known and fixed
>>> 
>>> An effective GPS jammer which can take out a few square miles is the size 
>>> of a trade paperback and runs on batteries and costs under 50 bucks to build
>>> 
>>> Imagine a scenario where a few hundred of these are deployed with hostile 
>>> intent.   
>>> 
>>> Military and Civillian systems are now useless due to nature of signal they 
>>> are hard to DF
>>> 
>>> Sent from my iPhone
>>> 
>>> On Jul 27, 2013, at 2:09 PM, Bob Camp  wrote:
>>> 
 Hi
 
 Loran can / could easily be jammed over a limited area, just like GPS. 
 Nothing crazy large or expensive would be required. The same sort of 
 "malfunctioning this or that" took out Loran from time to time over harbor 
 sized areas. Loran had so many issues with dropping out, that they simply 
 were not worth talking about ….
 
 Bob
 
 On Jul 27, 2013, at 1:35 PM, Scott McGrath  wrote:
 
> Key
> 
> Problem with GPS is its easy to spoof on one level and have a complete 
> denial of service on the other.   Out in California a while back a 
> malfunctioning TV distribution amplifier jammed a major harbor and 
> surrounding almost 25 sq miles affected all because of a 49.95 TV amp had 
> a problem.  The military receivers had the same problem
> 
> LORAN is virtually jam proof unless you have a very powerful transmitter
> 
> Sent from my iPhone
> 
> On Jul 27, 2013, at 11:17 AM, Michael Perrett  wrote:
> 
>> I have seen a lot of differing opinions on GPS Spoofing and using back up
>> systems on this thread. Most pretty good, but a couple off the mark a 
>> bit.
>> 
>> Here are a couple of comments on GPS Spoofing.
>> 
>> - There are anti-spoofing GPS receivers available - to "authorized"
>> users. Typically DOD. Most, if not all, military receivers utilize the
>> encrypted "P-Code", while civilians must use the more vulnerable clear 
>> text
>> "C/A code". The P-Code signals are very difficult to spoof unless you 
>> have
>> a-pirori knowledge. The newer satellites (GPS III) will have an even more
>> robust AS methodology.
>> - Note: beware of P-Code, or Military, receivers available on eBay.
>> They are useless without the encryption keys distributed by the US
>> Government.
>> - In the (near?) future there will be four civilian GPS Signals: "The
>> government is in the process of fielding three new signals designed for
>> civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or
>> C/A at L1, will continue broadcasting in the future, for a total of four
>> civil GPS signals. Users must upgrade their equipment to benefit from the
>> new signals". ref
>> http://www.gps.gov/systems/gps/modernization/civilsignals/
>> - Receivers utilizing the new civilian GPS frequencies can solve the GPS
>> equations from more than one frequency and see if any one signal is being
>> spoofed. The new civilian frequencies will be more spoof resistant.
>> 
>> Comments on using inertial measurement units (IMUs) to back up GPS.
>> 
>> - Current IMUs with even a "good" drift rate of say, 1 degree per hour,
>> available for around a few thousand dollars, will be off 60 nautical 
>> miles
>> after an hour of uncorrected operation. That can be reduced by other 
>> sensor
>> inputs (GPS, LORAN, pit-log or what ever you have), but the navigation
>> solution will eventually degrade to the accuracy of the external sensor. 
>> If
>> my memory serves me for a really deep pocket navigator (having tens 

Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Except a rotating rod antenna gives you only a bearing, not a direction. At VHF 
and above you can use multiple antennas and directly get a bearing. Much faster 
and easier to automate. 

Bob

On Jul 28, 2013, at 11:53 AM, Scott McGrath  wrote:

> Yes it is and it can be done with simple loop stick antennas. Prior to wide 
> use of loran ships would use LF beacons and DF receivers either manual 
> automatic 
> 
> Periodically you will see shortwave receivers with a rotating antenna and a 
> bearing ring you would find a bearing to a couple of beacon or broadcast 
> station and calculate position based on triangulation 
> 
> Basically a radio version of a pelorus 
> 
> 
> Sent from my iPhone
> 
> On Jul 28, 2013, at 5:03 AM, "stew...@g3ysx.org.uk"  
> wrote:
> 
>> LF is much easier to accurately DF than VHF and above due to multipath 
>> effects.
>> 
>> Stewart
>> 
>> Sent from my iPad
>> 
>> On 27 Jul 2013, at 21:44, Bob Camp  wrote:
>> 
>>> Hi
>>> 
>>> A Loran jammer would / could work with a *much* smaller antenna if a local 
>>> area was the target. Power is easy at 100 KHz. Loran is no easier / harder 
>>> to DF than GPS.
>>> 
>>> Bob
>>> 
>>> On Jul 27, 2013, at 3:37 PM, Scott McGrath  wrote:
>>> 
 LORAN was/is not perfect geographic features could and did limit reception 
   However an effective jammer would need effective power in the hundred 
 watt range and a efficient antenna system plus a connection to power grid 
 or small Genset.  
 
 Not amenable to easy concealment and fairly easy to DF using standard 
 techniques especially since location of real station well known and fixed
 
 An effective GPS jammer which can take out a few square miles is the size 
 of a trade paperback and runs on batteries and costs under 50 bucks to 
 build
 
 Imagine a scenario where a few hundred of these are deployed with hostile 
 intent.   
 
 Military and Civillian systems are now useless due to nature of signal 
 they are hard to DF
 
 Sent from my iPhone
 
 On Jul 27, 2013, at 2:09 PM, Bob Camp  wrote:
 
> Hi
> 
> Loran can / could easily be jammed over a limited area, just like GPS. 
> Nothing crazy large or expensive would be required. The same sort of 
> "malfunctioning this or that" took out Loran from time to time over 
> harbor sized areas. Loran had so many issues with dropping out, that they 
> simply were not worth talking about ….
> 
> Bob
> 
> On Jul 27, 2013, at 1:35 PM, Scott McGrath  wrote:
> 
>> Key
>> 
>> Problem with GPS is its easy to spoof on one level and have a complete 
>> denial of service on the other.   Out in California a while back a 
>> malfunctioning TV distribution amplifier jammed a major harbor and 
>> surrounding almost 25 sq miles affected all because of a 49.95 TV amp 
>> had a problem.  The military receivers had the same problem
>> 
>> LORAN is virtually jam proof unless you have a very powerful transmitter
>> 
>> Sent from my iPhone
>> 
>> On Jul 27, 2013, at 11:17 AM, Michael Perrett  
>> wrote:
>> 
>>> I have seen a lot of differing opinions on GPS Spoofing and using back 
>>> up
>>> systems on this thread. Most pretty good, but a couple off the mark a 
>>> bit.
>>> 
>>> Here are a couple of comments on GPS Spoofing.
>>> 
>>> - There are anti-spoofing GPS receivers available - to "authorized"
>>> users. Typically DOD. Most, if not all, military receivers utilize the
>>> encrypted "P-Code", while civilians must use the more vulnerable clear 
>>> text
>>> "C/A code". The P-Code signals are very difficult to spoof unless you 
>>> have
>>> a-pirori knowledge. The newer satellites (GPS III) will have an even 
>>> more
>>> robust AS methodology.
>>> - Note: beware of P-Code, or Military, receivers available on eBay.
>>> They are useless without the encryption keys distributed by the US
>>> Government.
>>> - In the (near?) future there will be four civilian GPS Signals: "The
>>> government is in the process of fielding three new signals designed for
>>> civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A 
>>> or
>>> C/A at L1, will continue broadcasting in the future, for a total of four
>>> civil GPS signals. Users must upgrade their equipment to benefit from 
>>> the
>>> new signals". ref
>>> http://www.gps.gov/systems/gps/modernization/civilsignals/
>>> - Receivers utilizing the new civilian GPS frequencies can solve the GPS
>>> equations from more than one frequency and see if any one signal is 
>>> being
>>> spoofed. The new civilian frequencies will be more spoof resistant.
>>> 
>>> Comments on using inertial measurement units (IMUs) to back up GPS.
>>> 
>>> - Current IMUs with even a "good" drift rate of say, 1 deg

Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

…. and if a pulse comes up *looking* like the slave ….

Loran-C wanders around enough all by it's self, with no need for help from 
others. Bumping it a bit this way or that is not an impossibility. A little bit 
of  added phase this way or that is all it would take. You would have to get 
the rep rate and timing right, but that's just the sort of thing a Time Nut 
knows how to do on the cheap. 

Bob

On Jul 28, 2013, at 11:55 AM, Poul-Henning Kamp  wrote:

> In message 
> 
> , Chris Albertson writes:
>> I think the GPS backups are called,
> 
> None of those are usable as backups for GPS, as they use the same
> low-power Microwave signals as GPS.
> 
>> But ALL radio navigation systems can be spoofed.   The ones you can't spoof
>> are
> 
> Loran-C.
> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

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Re: [time-nuts] GPS Spoofing

[Poul-Henning Kamp]

In message <26bb6f2a-69ac-4587-8057-ba18a03e8...@rtty.us>, Bob Camp writes:

>Bumping it a bit this way or that is not an impossibility. A little
>bit of  added phase this way or that is all it would take. You would have 
>to get the rep rate and timing right, but that's just the sort of thing a
>Time Nut knows how to do on the cheap. 

Only its not actually possible in practice.

The problem with GNSS is that the kit to jam/spoof is sub-suitcase-sized.

To jam/spoof LORAN-C or any other VLF system, you need several
trucks: One for the generator, one for the antenna -- at least.

That's the reason why LORSTA's have 600' antenna towers to begin with.

LORAN-C may not be as precise, but it is very stable, which means
that your dual-source nav-kit will tell you that GPS and LORAN-C
diverges in ways that looks odd...

The reason why we still have LORAN-C in europe, is that UK and
France don't trust DoD to not play with GPS.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] GPS Spoofing

[Scott McGrath]

Key is GPS is EASY to deny for wide areas for both Civillian and military users

Loran much less so and eLoran even less due to information carried by signal. 
And the larger the area attacked the jammer becomes easier to find due to 
signal strength 

There is no doubt that both systems can be spoofed by a sophisticated attacker. 
 

It's just that GPS can be nullified by jammers which are available at most 
truck and spy shops for under 200 bucks. Legality notwithstanding

Sent from my iPhone

On Jul 28, 2013, at 12:28 PM, Bob Camp  wrote:

> Hi
> 
> …. and if a pulse comes up *looking* like the slave ….
> 
> Loran-C wanders around enough all by it's self, with no need for help from 
> others. Bumping it a bit this way or that is not an impossibility. A little 
> bit of  added phase this way or that is all it would take. You would have to 
> get the rep rate and timing right, but that's just the sort of thing a Time 
> Nut knows how to do on the cheap. 
> 
> Bob
> 
> On Jul 28, 2013, at 11:55 AM, Poul-Henning Kamp  wrote:
> 
>> In message 
>> 
>> , Chris Albertson writes:
>>> I think the GPS backups are called,
>> 
>> None of those are usable as backups for GPS, as they use the same
>> low-power Microwave signals as GPS.
>> 
>>> But ALL radio navigation systems can be spoofed.   The ones you can't spoof
>>> are
>> 
>> Loran-C.
>> 
>> -- 
>> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
>> p...@freebsd.org | TCP/IP since RFC 956
>> FreeBSD committer   | BSD since 4.3-tahoe
>> Never attribute to malice what can adequately be explained by incompetence.
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
> 
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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

I'm not talking about taking out Loran-C over the entire North Atlantic. The 
target is a harbor sized area. For that, you certainly do not need a 600' 
antenna or megawatts of power. You only need to generate a near field signal, 
not set up something that will propagate beyond line of sight. There are a 
couple of ways that the antenna could be done. 

Long term, Loran-C is reasonably stable *if* the propagation is over water. If 
it's over land (as with most of the US chains) it's not as stable. A bit of 
drift from time to time was indeed very much expected. Great for getting back 
to last month's fishing spot, not quite so great for getting back to one from 
many years ago. 

Bob

On Jul 28, 2013, at 1:00 PM, "Poul-Henning Kamp"  wrote:

> In message <26bb6f2a-69ac-4587-8057-ba18a03e8...@rtty.us>, Bob Camp writes:
> 
>> Bumping it a bit this way or that is not an impossibility. A little
>> bit of  added phase this way or that is all it would take. You would have 
>> to get the rep rate and timing right, but that's just the sort of thing a
>> Time Nut knows how to do on the cheap. 
> 
> Only its not actually possible in practice.
> 
> The problem with GNSS is that the kit to jam/spoof is sub-suitcase-sized.
> 
> To jam/spoof LORAN-C or any other VLF system, you need several
> trucks: One for the generator, one for the antenna -- at least.
> 
> That's the reason why LORSTA's have 600' antenna towers to begin with.
> 
> LORAN-C may not be as precise, but it is very stable, which means
> that your dual-source nav-kit will tell you that GPS and LORAN-C
> diverges in ways that looks odd...
> 
> The reason why we still have LORAN-C in europe, is that UK and
> France don't trust DoD to not play with GPS.
> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.

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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

If we are now down to a truck sized / house sized area, I'd claim that Loran-C 
is dead simple to jam. That's what the truck stop gizmos are aimed at. 

Bob

On Jul 28, 2013, at 1:09 PM, Scott McGrath  wrote:

> Key is GPS is EASY to deny for wide areas for both Civillian and military 
> users
> 
> Loran much less so and eLoran even less due to information carried by signal. 
> And the larger the area attacked the jammer becomes easier to find due to 
> signal strength 
> 
> There is no doubt that both systems can be spoofed by a sophisticated 
> attacker.  
> 
> It's just that GPS can be nullified by jammers which are available at most 
> truck and spy shops for under 200 bucks. Legality notwithstanding
> 
> Sent from my iPhone
> 
> On Jul 28, 2013, at 12:28 PM, Bob Camp  wrote:
> 
>> Hi
>> 
>> …. and if a pulse comes up *looking* like the slave ….
>> 
>> Loran-C wanders around enough all by it's self, with no need for help from 
>> others. Bumping it a bit this way or that is not an impossibility. A little 
>> bit of  added phase this way or that is all it would take. You would have to 
>> get the rep rate and timing right, but that's just the sort of thing a Time 
>> Nut knows how to do on the cheap. 
>> 
>> Bob
>> 
>> On Jul 28, 2013, at 11:55 AM, Poul-Henning Kamp  wrote:
>> 
>>> In message 
>>> 
>>> , Chris Albertson writes:
 I think the GPS backups are called,
>>> 
>>> None of those are usable as backups for GPS, as they use the same
>>> low-power Microwave signals as GPS.
>>> 
 But ALL radio navigation systems can be spoofed.   The ones you can't spoof
 are
>>> 
>>> Loran-C.
>>> 
>>> -- 
>>> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
>>> p...@freebsd.org | TCP/IP since RFC 956
>>> FreeBSD committer   | BSD since 4.3-tahoe
>>> Never attribute to malice what can adequately be explained by incompetence.
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
>>> To unsubscribe, go to 
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>> 
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Re: [time-nuts] GPS Spoofing

[Poul-Henning Kamp]

In message <581a0abf-19d8-45bb-88c3-cb351711b...@rtty.us>, Bob Camp writes:

>If we are now down to a truck sized / house sized area, I'd claim that 
>Loran-C is dead simple to jam. That's what the truck stop gizmos are aimed at.

We are not.

You don't get to place your Loran-C jamming car right next to the supertanker
or cruise-ghetto, nor will any major airline allow your semi/van to emit EMI
from the parking-lot for long.

The problem with GNSS is that you need so little power and antenna to deny
such a large area.

VLF just doesn't suffer from that.

And now that US killed their LORAN, maybe we should apply some modern
signal-theory and design a new and even more robust VLF signal...

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] GPS Spoofing

[Poul-Henning Kamp]

In message , Bob Camp writes:

>I'm not talking about taking out Loran-C over the entire North Atlantic.
>The target is a harbor sized area. For that, you certainly do not need a
>600' antenna or megawatts of power.

No, you need about 600W (continuous) and a loop-antenna about 5m in diameter.

Do the math, It's not as easy as you think.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Since it's a pulse system, and you get to position your pulse for maximum 
effect, I don't see any reason to generate CW power. Simply mimic the lowest 
power slave in the chain. There's very little redundancy with Loran, so 
spoofing one station will mess it up. No need to mask the entire chain. At most 
you would need to hit two low power slaves. 

Math wise:

Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that and you have 
problems in a harbor. You would need to play a bit to see weather a pulse every 
so often does the trick or not. Is that 20 db below the slave or not ? You'd 
have to play with it. It's in that range. A spoof that says they are on the 
other side of the world isn't going to work. One that says you are on the north 
side of the channel (when you are on the south side) is what would work. 

Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI you have 
another 50:1. For longer GRI's you might add another 2:1. Net is a peak to 
average ratio of 250-1000 to 1. Put another way, a 500W pulse is ~ 1 average. 

Power at 100 KHz = what's in a fairly cheap switching power supply. Plug it 
into the wall. A couple hundred watts (or even KW) pulse is cheap. Say you have 
120W out of the wall (or a car battery). If the math above is correct and you 
can run 80% efficiency, that's a pretty powerful pulse. It's probably cheaper 
to generate something at 50:1 rather than the whole > 200:1. A 5KW is a *lot* 
of RF, even into a simple antenna. 

Antenna - there's a couple ways to do that. All of them are tradeoffs (size / 
cost / power). The cheap way is to use a wire that's already there…. Since you 
don't need to propagate (near field), the antenna  efficiency could be higher 
than you would think for some antennas. 

Is it easier than that with some smarts involved in the pulse - probably yes. 
Do the smarts raise the hardware cost significantly? - you'd have to build a 
few and find out. What really drives this or that Loran receiver nuts? I'm 
quite sure you could work that out with one to play with.

Am I gong into the Loran-C jammer business? No, so don't contact me off list to 
buy one. The point is not *have* I built one, but could one be built easily. 


Bob


On Jul 28, 2013, at 1:29 PM, "Poul-Henning Kamp"  wrote:

> In message , Bob Camp writes:
> 
>> I'm not talking about taking out Loran-C over the entire North Atlantic.
>> The target is a harbor sized area. For that, you certainly do not need a
>> 600' antenna or megawatts of power.
> 
> No, you need about 600W (continuous) and a loop-antenna about 5m in diameter.
> 
> Do the math, It's not as easy as you think.
> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.

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Re: [time-nuts] GPS Spoofing

[J. Forster]

The point about the duty cycle being low is correct. And, there are
commercial linear power amps, like the used ones made by ENI and others,
that can easily put out 1 kW plus narrow pulses.

Furthermore, the pulse generator is trivial to make with a Rb, 3 or more
Tektronix DD501s, a simple OR gate and a gated oscillator at about 100
kHz. I've cobbled up that setup several times as a LORAN-A simulator.

The main difficulty is getting a reasonable match to an efficient antenna
at 100 kHz.

-John

=



> Hi
>
> Since it's a pulse system, and you get to position your pulse for maximum
> effect, I don't see any reason to generate CW power. Simply mimic the
> lowest power slave in the chain. There's very little redundancy with
> Loran, so spoofing one station will mess it up. No need to mask the entire
> chain. At most you would need to hit two low power slaves.
>
> Math wise:
>
> Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that and you
> have problems in a harbor. You would need to play a bit to see weather a
> pulse every so often does the trick or not. Is that 20 db below the slave
> or not ? You'd have to play with it. It's in that range. A spoof that says
> they are on the other side of the world isn't going to work. One that says
> you are on the north side of the channel (when you are on the south side)
> is what would work.
>
> Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI you
> have another 50:1. For longer GRI's you might add another 2:1. Net is a
> peak to average ratio of 250-1000 to 1. Put another way, a 500W pulse is ~
> 1 average.
>
> Power at 100 KHz = what's in a fairly cheap switching power supply. Plug
> it into the wall. A couple hundred watts (or even KW) pulse is cheap. Say
> you have 120W out of the wall (or a car battery). If the math above is
> correct and you can run 80% efficiency, that's a pretty powerful pulse.
> It's probably cheaper to generate something at 50:1 rather than the whole
> > 200:1. A 5KW is a *lot* of RF, even into a simple antenna.
>
> Antenna - there's a couple ways to do that. All of them are tradeoffs
> (size / cost / power). The cheap way is to use a wire that's already
> there…. Since you don't need to propagate (near field), the antenna
> efficiency could be higher than you would think for some antennas.
>
> Is it easier than that with some smarts involved in the pulse - probably
> yes. Do the smarts raise the hardware cost significantly? - you'd have to
> build a few and find out. What really drives this or that Loran receiver
> nuts? I'm quite sure you could work that out with one to play with.
>
> Am I gong into the Loran-C jammer business? No, so don't contact me off
> list to buy one. The point is not *have* I built one, but could one be
> built easily.
>
>
> Bob
>
>
> On Jul 28, 2013, at 1:29 PM, "Poul-Henning Kamp" 
> wrote:
>
>> In message , Bob Camp
>> writes:
>>
>>> I'm not talking about taking out Loran-C over the entire North
>>> Atlantic.
>>> The target is a harbor sized area. For that, you certainly do not need
>>> a
>>> 600' antenna or megawatts of power.
>>
>> No, you need about 600W (continuous) and a loop-antenna about 5m in
>> diameter.
>>
>> Do the math, It's not as easy as you think.
>>
>> --
>> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
>> p...@freebsd.org | TCP/IP since RFC 956
>> FreeBSD committer   | BSD since 4.3-tahoe
>> Never attribute to malice what can adequately be explained by
>> incompetence.
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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>
>


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Re: [time-nuts] GPS Spoofing

[Rob Kimberley]

I've just been catching up on this thread. 

The subject says GPS Spoofing, but most of the replies seem to revolve
around jamming. Not the same thing.

Just a thought...

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of J. Forster
Sent: 28 July 2013 20:06
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS Spoofing

The point about the duty cycle being low is correct. And, there are
commercial linear power amps, like the used ones made by ENI and others,
that can easily put out 1 kW plus narrow pulses.

Furthermore, the pulse generator is trivial to make with a Rb, 3 or more
Tektronix DD501s, a simple OR gate and a gated oscillator at about 100 kHz.
I've cobbled up that setup several times as a LORAN-A simulator.

The main difficulty is getting a reasonable match to an efficient antenna at
100 kHz.

-John

=



> Hi
>
> Since it's a pulse system, and you get to position your pulse for 
> maximum effect, I don't see any reason to generate CW power. Simply 
> mimic the lowest power slave in the chain. There's very little 
> redundancy with Loran, so spoofing one station will mess it up. No 
> need to mask the entire chain. At most you would need to hit two low power
slaves.
>
> Math wise:
>
> Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that and 
> you have problems in a harbor. You would need to play a bit to see 
> weather a pulse every so often does the trick or not. Is that 20 db 
> below the slave or not ? You'd have to play with it. It's in that 
> range. A spoof that says they are on the other side of the world isn't 
> going to work. One that says you are on the north side of the channel 
> (when you are on the south side) is what would work.
>
> Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI you 
> have another 50:1. For longer GRI's you might add another 2:1. Net is 
> a peak to average ratio of 250-1000 to 1. Put another way, a 500W 
> pulse is ~
> 1 average.
>
> Power at 100 KHz = what's in a fairly cheap switching power supply. 
> Plug it into the wall. A couple hundred watts (or even KW) pulse is 
> cheap. Say you have 120W out of the wall (or a car battery). If the 
> math above is correct and you can run 80% efficiency, that's a pretty
powerful pulse.
> It's probably cheaper to generate something at 50:1 rather than the 
> whole
> > 200:1. A 5KW is a *lot* of RF, even into a simple antenna.
>
> Antenna - there's a couple ways to do that. All of them are tradeoffs 
> (size / cost / power). The cheap way is to use a wire that's already 
> there.. Since you don't need to propagate (near field), the antenna 
> efficiency could be higher than you would think for some antennas.
>
> Is it easier than that with some smarts involved in the pulse - 
> probably yes. Do the smarts raise the hardware cost significantly? - 
> you'd have to build a few and find out. What really drives this or 
> that Loran receiver nuts? I'm quite sure you could work that out with one
to play with.
>
> Am I gong into the Loran-C jammer business? No, so don't contact me 
> off list to buy one. The point is not *have* I built one, but could 
> one be built easily.
>
>
> Bob
>
>
> On Jul 28, 2013, at 1:29 PM, "Poul-Henning Kamp" 
> wrote:
>
>> In message , Bob Camp
>> writes:
>>
>>> I'm not talking about taking out Loran-C over the entire North 
>>> Atlantic.
>>> The target is a harbor sized area. For that, you certainly do not 
>>> need a 600' antenna or megawatts of power.
>>
>> No, you need about 600W (continuous) and a loop-antenna about 5m in 
>> diameter.
>>
>> Do the math, It's not as easy as you think.
>>
>> --
>> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
>> p...@freebsd.org | TCP/IP since RFC 956
>> FreeBSD committer   | BSD since 4.3-tahoe
>> Never attribute to malice what can adequately be explained by 
>> incompetence.
>
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>


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Re: [time-nuts] GPS Spoofing

[J. Forster]

Not so at all.

What I described is a simple means to make a receiver see different GRIs
and TDs than what it might see off the air. The system can accurately set
any GRI in 1 uS increments and any one of several TDs to 1 uS also. That
is hardly a jammer.

Furthermore, if the Tek DD501s were replaced by something like BNC
programmable Digital Delays, you could change the received position over
time.

-John





> I've just been catching up on this thread.
>
> The subject says GPS Spoofing, but most of the replies seem to revolve
> around jamming. Not the same thing.
>
> Just a thought...
>
> Rob
>
> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
> Behalf Of J. Forster
> Sent: 28 July 2013 20:06
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] GPS Spoofing
>
> The point about the duty cycle being low is correct. And, there are
> commercial linear power amps, like the used ones made by ENI and others,
> that can easily put out 1 kW plus narrow pulses.
>
> Furthermore, the pulse generator is trivial to make with a Rb, 3 or more
> Tektronix DD501s, a simple OR gate and a gated oscillator at about 100
> kHz.
> I've cobbled up that setup several times as a LORAN-A simulator.
>
> The main difficulty is getting a reasonable match to an efficient antenna
> at
> 100 kHz.
>
> -John
>
> =
>
>
>
>> Hi
>>
>> Since it's a pulse system, and you get to position your pulse for
>> maximum effect, I don't see any reason to generate CW power. Simply
>> mimic the lowest power slave in the chain. There's very little
>> redundancy with Loran, so spoofing one station will mess it up. No
>> need to mask the entire chain. At most you would need to hit two low
>> power
> slaves.
>>
>> Math wise:
>>
>> Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that and
>> you have problems in a harbor. You would need to play a bit to see
>> weather a pulse every so often does the trick or not. Is that 20 db
>> below the slave or not ? You'd have to play with it. It's in that
>> range. A spoof that says they are on the other side of the world isn't
>> going to work. One that says you are on the north side of the channel
>> (when you are on the south side) is what would work.
>>
>> Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI you
>> have another 50:1. For longer GRI's you might add another 2:1. Net is
>> a peak to average ratio of 250-1000 to 1. Put another way, a 500W
>> pulse is ~
>> 1 average.
>>
>> Power at 100 KHz = what's in a fairly cheap switching power supply.
>> Plug it into the wall. A couple hundred watts (or even KW) pulse is
>> cheap. Say you have 120W out of the wall (or a car battery). If the
>> math above is correct and you can run 80% efficiency, that's a pretty
> powerful pulse.
>> It's probably cheaper to generate something at 50:1 rather than the
>> whole
>> > 200:1. A 5KW is a *lot* of RF, even into a simple antenna.
>>
>> Antenna - there's a couple ways to do that. All of them are tradeoffs
>> (size / cost / power). The cheap way is to use a wire that's already
>> there.. Since you don't need to propagate (near field), the antenna
>> efficiency could be higher than you would think for some antennas.
>>
>> Is it easier than that with some smarts involved in the pulse -
>> probably yes. Do the smarts raise the hardware cost significantly? -
>> you'd have to build a few and find out. What really drives this or
>> that Loran receiver nuts? I'm quite sure you could work that out with
>> one
> to play with.
>>
>> Am I gong into the Loran-C jammer business? No, so don't contact me
>> off list to buy one. The point is not *have* I built one, but could
>> one be built easily.
>>
>>
>> Bob
>>
>>
>> On Jul 28, 2013, at 1:29 PM, "Poul-Henning Kamp" 
>> wrote:
>>
>>> In message , Bob Camp
>>> writes:
>>>
>>>> I'm not talking about taking out Loran-C over the entire North
>>>> Atlantic.
>>>> The target is a harbor sized area. For that, you certainly do not
>>>> need a 600' antenna or megawatts of power.
>>>
>>> No, you need about 600W (continuous) and a loop-antenna about 5m in
>>> diameter.
>>>
>>> Do the math, It's not as easy as you think.
>>>
&g

Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

My antenna "design" relies mainly on a near field / far field argument. In 
normal antenna design, the only thing that counts is the far field. You 
calculate the near field mainly to get drive point impedances. In this case you 
are within 1/10 wavelength of the antenna. The near field energy counts in this 
case. Propagation at 100 KHz is indeed polarization dependent. You also do not 
care about weather your antenna is horizontally or vertically polarized. 

One obvious design is a loop. It could be small, but quite high current. It 
could be larger / lower current. Switchers are often good at moving a lot of 
current into low impedances. Your "amp" might like a low impedance / high 
current load. Put another way - your amp may match to << 1 ohm. Think of a 3.3V 
100A switcher. Look especially at the sorts of currents inside the switching 
loop. Very much *not* a 50 ohm system.

Another design goes entirely the other way. Back feed the power lines. 
Horizontal polarization won't propagate, but that's not the issue. Impedance is 
low (yes I have measured it), so it's still a high current drive situation. 
Having the "signal" spread all over the neighborhood would be the main benefit. 

Are either of these "great" antennas? No, of course not. For that matter a 600' 
vertical isn't all that good an antenna at 100 KHz. That great big antenna is 
likely 200 to 600 miles away. 

Again, we're not trying to jam the system, only to spoof it by a bit. You don't 
need to drown out the slave transmitter. You just need to get the signals to 
add phase. 

Bob

On Jul 28, 2013, at 3:06 PM, "J. Forster"  wrote:

> The point about the duty cycle being low is correct. And, there are
> commercial linear power amps, like the used ones made by ENI and others,
> that can easily put out 1 kW plus narrow pulses.
> 
> Furthermore, the pulse generator is trivial to make with a Rb, 3 or more
> Tektronix DD501s, a simple OR gate and a gated oscillator at about 100
> kHz. I've cobbled up that setup several times as a LORAN-A simulator.
> 
> The main difficulty is getting a reasonable match to an efficient antenna
> at 100 kHz.
> 
> -John
> 
> =
> 
> 
> 
>> Hi
>> 
>> Since it's a pulse system, and you get to position your pulse for maximum
>> effect, I don't see any reason to generate CW power. Simply mimic the
>> lowest power slave in the chain. There's very little redundancy with
>> Loran, so spoofing one station will mess it up. No need to mask the entire
>> chain. At most you would need to hit two low power slaves.
>> 
>> Math wise:
>> 
>> Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that and you
>> have problems in a harbor. You would need to play a bit to see weather a
>> pulse every so often does the trick or not. Is that 20 db below the slave
>> or not ? You'd have to play with it. It's in that range. A spoof that says
>> they are on the other side of the world isn't going to work. One that says
>> you are on the north side of the channel (when you are on the south side)
>> is what would work.
>> 
>> Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI you
>> have another 50:1. For longer GRI's you might add another 2:1. Net is a
>> peak to average ratio of 250-1000 to 1. Put another way, a 500W pulse is ~
>> 1 average.
>> 
>> Power at 100 KHz = what's in a fairly cheap switching power supply. Plug
>> it into the wall. A couple hundred watts (or even KW) pulse is cheap. Say
>> you have 120W out of the wall (or a car battery). If the math above is
>> correct and you can run 80% efficiency, that's a pretty powerful pulse.
>> It's probably cheaper to generate something at 50:1 rather than the whole
>>> 200:1. A 5KW is a *lot* of RF, even into a simple antenna.
>> 
>> Antenna - there's a couple ways to do that. All of them are tradeoffs
>> (size / cost / power). The cheap way is to use a wire that's already
>> there…. Since you don't need to propagate (near field), the antenna
>> efficiency could be higher than you would think for some antennas.
>> 
>> Is it easier than that with some smarts involved in the pulse - probably
>> yes. Do the smarts raise the hardware cost significantly? - you'd have to
>> build a few and find out. What really drives this or that Loran receiver
>> nuts? I'm quite sure you could work that out with one to play with.
>> 
>> Am I gong into the Loran-C jammer business? No, so don't contact me off
>> list to buy one. The point is not *have* I built one, but could one be
>> built easily.
>> 
>> 
>> Bob
>> 
>> 
>> On Jul 28, 2013, at 1:29 PM, "Poul-Henning Kamp" 
>> wrote:
>> 
>>> In message , Bob Camp
>>> writes:
>>> 
 I'm not talking about taking out Loran-C over the entire North
 Atlantic.
 The target is a harbor sized area. For that, you certainly do not need
 a
 600' antenna or megawatts of power.
>>> 
>>> No, you need about 600W (continuous) and a loop-antenna about 5m in
>>> diameter.
>>> 
>>> Do the math, It's not as easy as you 

Re: [time-nuts] GPS Spoofing

[Tom Miller]

You can't use "efficient antenna" and "100 kHz" in the same sentence. Oh, 
wait...



- Original Message - 
From: "J. Forster" 
To: "Discussion of precise time and frequency measurement" 


Sent: Sunday, July 28, 2013 3:06 PM
Subject: Re: [time-nuts] GPS Spoofing


The point about the duty cycle being low is correct. And, there are
commercial linear power amps, like the used ones made by ENI and others,
that can easily put out 1 kW plus narrow pulses.

Furthermore, the pulse generator is trivial to make with a Rb, 3 or more
Tektronix DD501s, a simple OR gate and a gated oscillator at about 100
kHz. I've cobbled up that setup several times as a LORAN-A simulator.

The main difficulty is getting a reasonable match to an efficient antenna
at 100 kHz.

-John

=




Hi

Since it's a pulse system, and you get to position your pulse for maximum
effect, I don't see any reason to generate CW power. Simply mimic the
lowest power slave in the chain. There's very little redundancy with
Loran, so spoofing one station will mess it up. No need to mask the entire
chain. At most you would need to hit two low power slaves.

Math wise:

Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that and you
have problems in a harbor. You would need to play a bit to see weather a
pulse every so often does the trick or not. Is that 20 db below the slave
or not ? You'd have to play with it. It's in that range. A spoof that says
they are on the other side of the world isn't going to work. One that says
you are on the north side of the channel (when you are on the south side)
is what would work.

Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI you
have another 50:1. For longer GRI's you might add another 2:1. Net is a
peak to average ratio of 250-1000 to 1. Put another way, a 500W pulse is ~
1 average.

Power at 100 KHz = what's in a fairly cheap switching power supply. Plug
it into the wall. A couple hundred watts (or even KW) pulse is cheap. Say
you have 120W out of the wall (or a car battery). If the math above is
correct and you can run 80% efficiency, that's a pretty powerful pulse.
It's probably cheaper to generate something at 50:1 rather than the whole
> 200:1. A 5KW is a *lot* of RF, even into a simple antenna.

Antenna - there's a couple ways to do that. All of them are tradeoffs
(size / cost / power). The cheap way is to use a wire that's already
there…. Since you don't need to propagate (near field), the antenna
efficiency could be higher than you would think for some antennas.

Is it easier than that with some smarts involved in the pulse - probably
yes. Do the smarts raise the hardware cost significantly? - you'd have to
build a few and find out. What really drives this or that Loran receiver
nuts? I'm quite sure you could work that out with one to play with.

Am I gong into the Loran-C jammer business? No, so don't contact me off
list to buy one. The point is not *have* I built one, but could one be
built easily.


Bob


On Jul 28, 2013, at 1:29 PM, "Poul-Henning Kamp" 
wrote:


In message , Bob Camp
writes:


I'm not talking about taking out Loran-C over the entire North
Atlantic.
The target is a harbor sized area. For that, you certainly do not need
a
600' antenna or megawatts of power.


No, you need about 600W (continuous) and a loop-antenna about 5m in
diameter.

Do the math, It's not as easy as you think.

--
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by
incompetence.


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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

So in this case we're talking about "horrible" to "even more horrible" in terms 
of efficiency. I'll freely grant that a 600' tower over a really good ground 
plane (like say the sea) is going to be way more efficient than anything I'd 
come up with. The same thing would apply to a matching network made of coils 
you can stand up inside compared to anything I'd make. 

Totally off topic - In the lobby of Continental Electronics they used to have 
this typical transmitter sitting there. You sort of wondered "why". After 
looking at it you figured out the little ant down in the bottom was a person. 
Yes, the coils and "stuff" in Omega transmitters were *big*.

Bob

On Jul 28, 2013, at 4:23 PM, Tom Miller  wrote:

> You can't use "efficient antenna" and "100 kHz" in the same sentence. Oh, 
> wait...
> 
> 
> - Original Message - From: "J. Forster" 
> To: "Discussion of precise time and frequency measurement" 
> 
> Sent: Sunday, July 28, 2013 3:06 PM
> Subject: Re: [time-nuts] GPS Spoofing
> 
> 
> The point about the duty cycle being low is correct. And, there are
> commercial linear power amps, like the used ones made by ENI and others,
> that can easily put out 1 kW plus narrow pulses.
> 
> Furthermore, the pulse generator is trivial to make with a Rb, 3 or more
> Tektronix DD501s, a simple OR gate and a gated oscillator at about 100
> kHz. I've cobbled up that setup several times as a LORAN-A simulator.
> 
> The main difficulty is getting a reasonable match to an efficient antenna
> at 100 kHz.
> 
> -John
> 
> =
> 
> 
> 
>> Hi
>> 
>> Since it's a pulse system, and you get to position your pulse for maximum
>> effect, I don't see any reason to generate CW power. Simply mimic the
>> lowest power slave in the chain. There's very little redundancy with
>> Loran, so spoofing one station will mess it up. No need to mask the entire
>> chain. At most you would need to hit two low power slaves.
>> 
>> Math wise:
>> 
>> Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that and you
>> have problems in a harbor. You would need to play a bit to see weather a
>> pulse every so often does the trick or not. Is that 20 db below the slave
>> or not ? You'd have to play with it. It's in that range. A spoof that says
>> they are on the other side of the world isn't going to work. One that says
>> you are on the north side of the channel (when you are on the south side)
>> is what would work.
>> 
>> Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI you
>> have another 50:1. For longer GRI's you might add another 2:1. Net is a
>> peak to average ratio of 250-1000 to 1. Put another way, a 500W pulse is ~
>> 1 average.
>> 
>> Power at 100 KHz = what's in a fairly cheap switching power supply. Plug
>> it into the wall. A couple hundred watts (or even KW) pulse is cheap. Say
>> you have 120W out of the wall (or a car battery). If the math above is
>> correct and you can run 80% efficiency, that's a pretty powerful pulse.
>> It's probably cheaper to generate something at 50:1 rather than the whole
>> > 200:1. A 5KW is a *lot* of RF, even into a simple antenna.
>> 
>> Antenna - there's a couple ways to do that. All of them are tradeoffs
>> (size / cost / power). The cheap way is to use a wire that's already
>> there…. Since you don't need to propagate (near field), the antenna
>> efficiency could be higher than you would think for some antennas.
>> 
>> Is it easier than that with some smarts involved in the pulse - probably
>> yes. Do the smarts raise the hardware cost significantly? - you'd have to
>> build a few and find out. What really drives this or that Loran receiver
>> nuts? I'm quite sure you could work that out with one to play with.
>> 
>> Am I gong into the Loran-C jammer business? No, so don't contact me off
>> list to buy one. The point is not *have* I built one, but could one be
>> built easily.
>> 
>> 
>> Bob
>> 
>> 
>> On Jul 28, 2013, at 1:29 PM, "Poul-Henning Kamp" 
>> wrote:
>> 
>>> In message , Bob Camp
>>> writes:
>>> 
>>>> I'm not talking about taking out Loran-C over the entire North
>>>> Atlantic.
>>>> The target is a harbor sized area. For that, you certainly do not need
>>>> a
>>>> 600' antenna or megawatts of power.
>>> 
>>> No, you need abou

Re: [time-nuts] GPS Spoofing

[Bob Stewart]

So, given the size of a typical freighter these days, what's so hard about 
imagining one with enough wire in the air to make that happen for whatever 
political or commercial reason?

Bob





>
> From: Bob Camp 
>To: Discussion of precise time and frequency measurement  
>Sent: Sunday, July 28, 2013 4:05 PM
>Subject: Re: [time-nuts] GPS Spoofing
> 
>
>Hi
>
>So in this case we're talking about "horrible" to "even more horrible" in 
>terms of efficiency. I'll freely grant that a 600' tower over a really good 
>ground plane (like say the sea) is going to be way more efficient than 
>anything I'd come up with. The same thing would apply to a matching network 
>made of coils you can stand up inside compared to anything I'd make. 
>
>Totally off topic - In the lobby of Continental Electronics they used to have 
>this typical transmitter sitting there. You sort of wondered "why". After 
>looking at it you figured out the little ant down in the bottom was a person. 
>Yes, the coils and "stuff" in Omega transmitters were *big*.
>
>Bob
>
>
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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Small antennas (all antennas at 100 KHz are small) are not a matter of 
wavelengths of wire in the air. They are a matter of making do with what you 
have. Efficiency is more a matter of coil loss (or equivalent) than of antenna 
size.

Bob

On Jul 28, 2013, at 5:12 PM, Bob Stewart  wrote:

> So, given the size of a typical freighter these days, what's so hard about 
> imagining one with enough wire in the air to make that happen for whatever 
> political or commercial reason?
> 
> Bob
> 
> 
> 
> 
> 
>> 
>> From: Bob Camp 
>> To: Discussion of precise time and frequency measurement 
>>  
>> Sent: Sunday, July 28, 2013 4:05 PM
>> Subject: Re: [time-nuts] GPS Spoofing
>> 
>> 
>> Hi
>> 
>> So in this case we're talking about "horrible" to "even more horrible" in 
>> terms of efficiency. I'll freely grant that a 600' tower over a really good 
>> ground plane (like say the sea) is going to be way more efficient than 
>> anything I'd come up with. The same thing would apply to a matching network 
>> made of coils you can stand up inside compared to anything I'd make. 
>> 
>> Totally off topic - In the lobby of Continental Electronics they used to 
>> have this typical transmitter sitting there. You sort of wondered "why". 
>> After looking at it you figured out the little ant down in the bottom was a 
>> person. Yes, the coils and "stuff" in Omega transmitters were *big*.
>> 
>> Bob
>> 
>> 
> ___
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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Actually not the whole story.

Propagating (far field) antennas are also a function of producing the 
polarization you want and a good field remote from the antenna. For instance, 
you can get  a really good field inside a toroid, but it's not a good far filed 
(or near field) antenna.

Bob

On Jul 28, 2013, at 5:23 PM, Bob Camp  wrote:

> Hi
> 
> Small antennas (all antennas at 100 KHz are small) are not a matter of 
> wavelengths of wire in the air. They are a matter of making do with what you 
> have. Efficiency is more a matter of coil loss (or equivalent) than of 
> antenna size.
> 
> Bob
> 
> On Jul 28, 2013, at 5:12 PM, Bob Stewart  wrote:
> 
>> So, given the size of a typical freighter these days, what's so hard about 
>> imagining one with enough wire in the air to make that happen for whatever 
>> political or commercial reason?
>> 
>> Bob
>> 
>> 
>> 
>> 
>> 
>>> 
>>> From: Bob Camp 
>>> To: Discussion of precise time and frequency measurement 
>>>  
>>> Sent: Sunday, July 28, 2013 4:05 PM
>>> Subject: Re: [time-nuts] GPS Spoofing
>>> 
>>> 
>>> Hi
>>> 
>>> So in this case we're talking about "horrible" to "even more horrible" in 
>>> terms of efficiency. I'll freely grant that a 600' tower over a really good 
>>> ground plane (like say the sea) is going to be way more efficient than 
>>> anything I'd come up with. The same thing would apply to a matching network 
>>> made of coils you can stand up inside compared to anything I'd make. 
>>> 
>>> Totally off topic - In the lobby of Continental Electronics they used to 
>>> have this typical transmitter sitting there. You sort of wondered "why". 
>>> After looking at it you figured out the little ant down in the bottom was a 
>>> person. Yes, the coils and "stuff" in Omega transmitters were *big*.
>>> 
>>> Bob
>>> 
>>> 
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
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>> and follow the instructions there.
> 
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Re: [time-nuts] GPS Spoofing

[Tom Miller]

That is why they use litz wire, sometimes three inches in diameter for the 
coils and for the capacity hat.


The ground system includes miles of buried copper. Capacitors are larger 
than trash cans and gas filled.




- Original Message - 
From: "Bob Camp" 
To: "Discussion of precise time and frequency measurement" 


Sent: Sunday, July 28, 2013 5:23 PM
Subject: Re: [time-nuts] GPS Spoofing


Hi

Small antennas (all antennas at 100 KHz are small) are not a matter of 
wavelengths of wire in the air. They are a matter of making do with what you 
have. Efficiency is more a matter of coil loss (or equivalent) than of 
antenna size.


Bob

On Jul 28, 2013, at 5:12 PM, Bob Stewart  wrote:

So, given the size of a typical freighter these days, what's so hard about 
imagining one with enough wire in the air to make that happen for whatever 
political or commercial reason?


Bob







From: Bob Camp 
To: Discussion of precise time and frequency measurement 


Sent: Sunday, July 28, 2013 4:05 PM
Subject: Re: [time-nuts] GPS Spoofing


Hi

So in this case we're talking about "horrible" to "even more horrible" in 
terms of efficiency. I'll freely grant that a 600' tower over a really 
good ground plane (like say the sea) is going to be way more efficient 
than anything I'd come up with. The same thing would apply to a matching 
network made of coils you can stand up inside compared to anything I'd 
make.


Totally off topic - In the lobby of Continental Electronics they used to 
have this typical transmitter sitting there. You sort of wondered "why". 
After looking at it you figured out the little ant down in the bottom was 
a person. Yes, the coils and "stuff" in Omega transmitters were *big*.


Bob



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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Part (but not all) of that is related to handling >= 400KW pulses. A bit of it 
also relates to handling lightning hits on the tower. 

Bob

On Jul 28, 2013, at 5:39 PM, "Tom Miller"  wrote:

> That is why they use litz wire, sometimes three inches in diameter for the 
> coils and for the capacity hat.
> 
> The ground system includes miles of buried copper. Capacitors are larger than 
> trash cans and gas filled.
> 
> 
> 
> - Original Message - From: "Bob Camp" 
> To: "Discussion of precise time and frequency measurement" 
> 
> Sent: Sunday, July 28, 2013 5:23 PM
> Subject: Re: [time-nuts] GPS Spoofing
> 
> 
> Hi
> 
> Small antennas (all antennas at 100 KHz are small) are not a matter of 
> wavelengths of wire in the air. They are a matter of making do with what you 
> have. Efficiency is more a matter of coil loss (or equivalent) than of 
> antenna size.
> 
> Bob
> 
> On Jul 28, 2013, at 5:12 PM, Bob Stewart  wrote:
> 
>> So, given the size of a typical freighter these days, what's so hard about 
>> imagining one with enough wire in the air to make that happen for whatever 
>> political or commercial reason?
>> 
>> Bob
>> 
>> 
>> 
>> 
>> 
>>> ________
>>> From: Bob Camp 
>>> To: Discussion of precise time and frequency measurement 
>>> 
>>> Sent: Sunday, July 28, 2013 4:05 PM
>>> Subject: Re: [time-nuts] GPS Spoofing
>>> 
>>> 
>>> Hi
>>> 
>>> So in this case we're talking about "horrible" to "even more horrible" in 
>>> terms of efficiency. I'll freely grant that a 600' tower over a really good 
>>> ground plane (like say the sea) is going to be way more efficient than 
>>> anything I'd come up with. The same thing would apply to a matching network 
>>> made of coils you can stand up inside compared to anything I'd make.
>>> 
>>> Totally off topic - In the lobby of Continental Electronics they used to 
>>> have this typical transmitter sitting there. You sort of wondered "why". 
>>> After looking at it you figured out the little ant down in the bottom was a 
>>> person. Yes, the coils and "stuff" in Omega transmitters were *big*.
>>> 
>>> Bob
>>> 
>>> 
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
> 
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Re: [time-nuts] GPS Spoofing

[Mark C. Stephens]

No better ground plane than salt water...


--marki

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Bob Stewart
Sent: Monday, 29 July 2013 7:13 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS Spoofing

So, given the size of a typical freighter these days, what's so hard about 
imagining one with enough wire in the air to make that happen for whatever 
political or commercial reason?

Bob





>
> From: Bob Camp 
>To: Discussion of precise time and frequency measurement 
>
>Sent: Sunday, July 28, 2013 4:05 PM
>Subject: Re: [time-nuts] GPS Spoofing
> 
>
>Hi
>
>So in this case we're talking about "horrible" to "even more horrible" in 
>terms of efficiency. I'll freely grant that a 600' tower over a really good 
>ground plane (like say the sea) is going to be way more efficient than 
>anything I'd come up with. The same thing would apply to a matching network 
>made of coils you can stand up inside compared to anything I'd make. 
>
>Totally off topic - In the lobby of Continental Electronics they used to have 
>this typical transmitter sitting there. You sort of wondered "why". After 
>looking at it you figured out the little ant down in the bottom was a person. 
>Yes, the coils and "stuff" in Omega transmitters were *big*.
>
>Bob
>
>
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Re: [time-nuts] GPS Spoofing

[Mark C. Stephens]

The Helix coils are 25' high and have a 6' high relay: 
http://www.haikuvalley.com/History/OMEGA-NAVIGATION-SYSTEM/8839335_kzKJLd#!i=2042047390&k=QJbHKzM/


--marki


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Bob Camp
Sent: Monday, 29 July 2013 7:05 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS Spoofing

Hi

So in this case we're talking about "horrible" to "even more horrible" in terms 
of efficiency. I'll freely grant that a 600' tower over a really good ground 
plane (like say the sea) is going to be way more efficient than anything I'd 
come up with. The same thing would apply to a matching network made of coils 
you can stand up inside compared to anything I'd make. 

Totally off topic - In the lobby of Continental Electronics they used to have 
this typical transmitter sitting there. You sort of wondered "why". After 
looking at it you figured out the little ant down in the bottom was a person. 
Yes, the coils and "stuff" in Omega transmitters were *big*.

Bob

On Jul 28, 2013, at 4:23 PM, Tom Miller  wrote:

> You can't use "efficient antenna" and "100 kHz" in the same sentence. Oh, 
> wait...
> 
> 
> - Original Message - From: "J. Forster" 
> To: "Discussion of precise time and frequency measurement" 
> 
> Sent: Sunday, July 28, 2013 3:06 PM
> Subject: Re: [time-nuts] GPS Spoofing
> 
> 
> The point about the duty cycle being low is correct. And, there are 
> commercial linear power amps, like the used ones made by ENI and 
> others, that can easily put out 1 kW plus narrow pulses.
> 
> Furthermore, the pulse generator is trivial to make with a Rb, 3 or 
> more Tektronix DD501s, a simple OR gate and a gated oscillator at 
> about 100 kHz. I've cobbled up that setup several times as a LORAN-A 
> simulator.
> 
> The main difficulty is getting a reasonable match to an efficient 
> antenna at 100 kHz.
> 
> -John
> 
> =
> 
> 
> 
>> Hi
>> 
>> Since it's a pulse system, and you get to position your pulse for 
>> maximum effect, I don't see any reason to generate CW power. Simply 
>> mimic the lowest power slave in the chain. There's very little 
>> redundancy with Loran, so spoofing one station will mess it up. No 
>> need to mask the entire chain. At most you would need to hit two low power 
>> slaves.
>> 
>> Math wise:
>> 
>> Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that 
>> and you have problems in a harbor. You would need to play a bit to 
>> see weather a pulse every so often does the trick or not. Is that 20 
>> db below the slave or not ? You'd have to play with it. It's in that 
>> range. A spoof that says they are on the other side of the world 
>> isn't going to work. One that says you are on the north side of the 
>> channel (when you are on the south side) is what would work.
>> 
>> Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI 
>> you have another 50:1. For longer GRI's you might add another 2:1. 
>> Net is a peak to average ratio of 250-1000 to 1. Put another way, a 
>> 500W pulse is ~
>> 1 average.
>> 
>> Power at 100 KHz = what's in a fairly cheap switching power supply. 
>> Plug it into the wall. A couple hundred watts (or even KW) pulse is 
>> cheap. Say you have 120W out of the wall (or a car battery). If the 
>> math above is correct and you can run 80% efficiency, that's a pretty 
>> powerful pulse.
>> It's probably cheaper to generate something at 50:1 rather than the 
>> whole
>> > 200:1. A 5KW is a *lot* of RF, even into a simple antenna.
>> 
>> Antenna - there's a couple ways to do that. All of them are tradeoffs 
>> (size / cost / power). The cheap way is to use a wire that's already 
>> there Since you don't need to propagate (near field), the antenna 
>> efficiency could be higher than you would think for some antennas.
>> 
>> Is it easier than that with some smarts involved in the pulse - 
>> probably yes. Do the smarts raise the hardware cost significantly? - 
>> you'd have to build a few and find out. What really drives this or 
>> that Loran receiver nuts? I'm quite sure you could work that out with one to 
>> play with.
>> 
>> Am I gong into the Loran-C jammer business? No, so don't contact me 
>> off list to buy one. The point is not *have* I built one, but could 
>> one be built easily.
>> 
>> 
>>

Re: [time-nuts] GPS Spoofing

[J. Forster]

I'm not so convinced about this:

"OMEGA was the primary means of radio navigation, world wide, from 1976 to
1997. ."

There was LORAN-C, after all.

And Omega was a CW, phase difference system, LORAN a pulse system.

AFAIK, Omega never really made it into the uP age; LORAN certainly did.

-John

===






> The Helix coils are 25' high and have a 6' high relay:
> http://www.haikuvalley.com/History/OMEGA-NAVIGATION-SYSTEM/8839335_kzKJLd#!i=2042047390&k=QJbHKzM/
>
>
> --marki
>
>
> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
> Behalf Of Bob Camp
> Sent: Monday, 29 July 2013 7:05 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] GPS Spoofing
>
> Hi
>
> So in this case we're talking about "horrible" to "even more horrible" in
> terms of efficiency. I'll freely grant that a 600' tower over a really
> good ground plane (like say the sea) is going to be way more efficient
> than anything I'd come up with. The same thing would apply to a matching
> network made of coils you can stand up inside compared to anything I'd
> make.
>
> Totally off topic - In the lobby of Continental Electronics they used to
> have this typical transmitter sitting there. You sort of wondered "why".
> After looking at it you figured out the little ant down in the bottom was
> a person. Yes, the coils and "stuff" in Omega transmitters were *big*.
>
> Bob
>
> On Jul 28, 2013, at 4:23 PM, Tom Miller  wrote:
>
>> You can't use "efficient antenna" and "100 kHz" in the same sentence.
>> Oh, wait...
>>
>>
>> - Original Message - From: "J. Forster" 
>> To: "Discussion of precise time and frequency measurement"
>> 
>> Sent: Sunday, July 28, 2013 3:06 PM
>> Subject: Re: [time-nuts] GPS Spoofing
>>
>>
>> The point about the duty cycle being low is correct. And, there are
>> commercial linear power amps, like the used ones made by ENI and
>> others, that can easily put out 1 kW plus narrow pulses.
>>
>> Furthermore, the pulse generator is trivial to make with a Rb, 3 or
>> more Tektronix DD501s, a simple OR gate and a gated oscillator at
>> about 100 kHz. I've cobbled up that setup several times as a LORAN-A
>> simulator.
>>
>> The main difficulty is getting a reasonable match to an efficient
>> antenna at 100 kHz.
>>
>> -John
>>
>> =
>>
>>
>>
>>> Hi
>>>
>>> Since it's a pulse system, and you get to position your pulse for
>>> maximum effect, I don't see any reason to generate CW power. Simply
>>> mimic the lowest power slave in the chain. There's very little
>>> redundancy with Loran, so spoofing one station will mess it up. No
>>> need to mask the entire chain. At most you would need to hit two low
>>> power slaves.
>>>
>>> Math wise:
>>>
>>> Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that
>>> and you have problems in a harbor. You would need to play a bit to
>>> see weather a pulse every so often does the trick or not. Is that 20
>>> db below the slave or not ? You'd have to play with it. It's in that
>>> range. A spoof that says they are on the other side of the world
>>> isn't going to work. One that says you are on the north side of the
>>> channel (when you are on the south side) is what would work.
>>>
>>> Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI
>>> you have another 50:1. For longer GRI's you might add another 2:1.
>>> Net is a peak to average ratio of 250-1000 to 1. Put another way, a
>>> 500W pulse is ~
>>> 1 average.
>>>
>>> Power at 100 KHz = what's in a fairly cheap switching power supply.
>>> Plug it into the wall. A couple hundred watts (or even KW) pulse is
>>> cheap. Say you have 120W out of the wall (or a car battery). If the
>>> math above is correct and you can run 80% efficiency, that's a pretty
>>> powerful pulse.
>>> It's probably cheaper to generate something at 50:1 rather than the
>>> whole
>>> > 200:1. A 5KW is a *lot* of RF, even into a simple antenna.
>>>
>>> Antenna - there's a couple ways to do that. All of them are tradeoffs
>>> (size / cost / power). The cheap way is to use a wire that's already
>>> there Since you don't need to propagate

Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Omega was world wide, Loran was not. Anything that operated over *long* 
distances (tankers, airplanes) was Omega. They pulled Omega gear off of the 
planes and replaced it with GPS. I suspect they did the same thing on the big 
tankers.

Bob

On Jul 28, 2013, at 6:24 PM, "J. Forster"  wrote:

> I'm not so convinced about this:
> 
> "OMEGA was the primary means of radio navigation, world wide, from 1976 to
> 1997. ."
> 
> There was LORAN-C, after all.
> 
> And Omega was a CW, phase difference system, LORAN a pulse system.
> 
> AFAIK, Omega never really made it into the uP age; LORAN certainly did.
> 
> -John
> 
> ===
> 
> 
> 
> 
> 
> 
>> The Helix coils are 25' high and have a 6' high relay:
>> http://www.haikuvalley.com/History/OMEGA-NAVIGATION-SYSTEM/8839335_kzKJLd#!i=2042047390&k=QJbHKzM/
>> 
>> 
>> --marki
>> 
>> 
>> -Original Message-
>> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
>> Behalf Of Bob Camp
>> Sent: Monday, 29 July 2013 7:05 AM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] GPS Spoofing
>> 
>> Hi
>> 
>> So in this case we're talking about "horrible" to "even more horrible" in
>> terms of efficiency. I'll freely grant that a 600' tower over a really
>> good ground plane (like say the sea) is going to be way more efficient
>> than anything I'd come up with. The same thing would apply to a matching
>> network made of coils you can stand up inside compared to anything I'd
>> make.
>> 
>> Totally off topic - In the lobby of Continental Electronics they used to
>> have this typical transmitter sitting there. You sort of wondered "why".
>> After looking at it you figured out the little ant down in the bottom was
>> a person. Yes, the coils and "stuff" in Omega transmitters were *big*.
>> 
>> Bob
>> 
>> On Jul 28, 2013, at 4:23 PM, Tom Miller  wrote:
>> 
>>> You can't use "efficient antenna" and "100 kHz" in the same sentence.
>>> Oh, wait...
>>> 
>>> 
>>> - Original Message - From: "J. Forster" 
>>> To: "Discussion of precise time and frequency measurement"
>>> 
>>> Sent: Sunday, July 28, 2013 3:06 PM
>>> Subject: Re: [time-nuts] GPS Spoofing
>>> 
>>> 
>>> The point about the duty cycle being low is correct. And, there are
>>> commercial linear power amps, like the used ones made by ENI and
>>> others, that can easily put out 1 kW plus narrow pulses.
>>> 
>>> Furthermore, the pulse generator is trivial to make with a Rb, 3 or
>>> more Tektronix DD501s, a simple OR gate and a gated oscillator at
>>> about 100 kHz. I've cobbled up that setup several times as a LORAN-A
>>> simulator.
>>> 
>>> The main difficulty is getting a reasonable match to an efficient
>>> antenna at 100 kHz.
>>> 
>>> -John
>>> 
>>> =
>>> 
>>> 
>>> 
>>>> Hi
>>>> 
>>>> Since it's a pulse system, and you get to position your pulse for
>>>> maximum effect, I don't see any reason to generate CW power. Simply
>>>> mimic the lowest power slave in the chain. There's very little
>>>> redundancy with Loran, so spoofing one station will mess it up. No
>>>> need to mask the entire chain. At most you would need to hit two low
>>>> power slaves.
>>>> 
>>>> Math wise:
>>>> 
>>>> Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that
>>>> and you have problems in a harbor. You would need to play a bit to
>>>> see weather a pulse every so often does the trick or not. Is that 20
>>>> db below the slave or not ? You'd have to play with it. It's in that
>>>> range. A spoof that says they are on the other side of the world
>>>> isn't going to work. One that says you are on the north side of the
>>>> channel (when you are on the south side) is what would work.
>>>> 
>>>> Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI
>>>> you have another 50:1. For longer GRI's you might add another 2:1.
>>>> Net is a peak to average ratio of 250-1000 to 1. Put another way, a
>>>> 500W pulse is ~
>>>> 1 average.
>>>> 
>>>> Po

Re: [time-nuts] GPS Spoofing

[Grant Saviers]

Interesting comments about navigation of ships and GPS spoofing 
potential.  As a recreational offshore captain/navigator, over the years 
I've used a few generations each of RDF, Loran, GPS, and radar.  My most 
recent extended nautical travels have been on 100 passenger 
"exploration" ships, 300' +/- with open bridge policies, where I spent a 
fair amount of time with the crews in different oceans of the world.


Disasters are most often caused by stupid, drunk, or asleep 
captains/crews, not by the electronics.  Further, the SOLAS regs for all 
commercial ships require a lot of redundancy, a minimum two each radars, 
AIS, and GPS and more are usually on the bridge.  There may be a 
"molasses tanker" out there with only a compass, but it is illegal and 
isn't going into any managed port in the world.


In any close to obstruction/land situation, radar, visual fixes, and 
soundings are the primary redundant navigation tools.  GPS is mostly 
ignored as a position plot tool, except for anchor watch, once 
anchored.Electronic charts, often integrated with the radar are one 
plot tool and paper charts with detailed course plots, soundings, and 
visual fixes are another.


Offshore navigation is a different ball game, mostly radar and visual 
watches and hourly GPS position plots by the navigator in the log and on 
the paper voyage chart.  AIS is required on all ships and that makes the 
radar returns much more useful.  Current radars, with integrated AIS, 
all the plotting tools for traffic, closest approach plots, etc. get 
constant attention.  As mentioned, underway, a GPS often updates the 
autopilot course setting, usually track mode to avoid current drift.  A 
magnetic/gyro/inertial compass system corrects the autopilot for real 
time rudder control.


Navigation tool redundancy and crew alertness keeps ships from going 
where the ducks are walking.


Charts are frequently suspect.  On one cruise, we were in an estuary in 
remote NW Australia, nothing but blue water on the chart, no soundings, 
no depth contours.  I asked the captain about this, a bit surprising to 
me to be there in a large ship.  He had been there before, saved the 
prior successful GPS plot, and that in combination with go slow, forward 
looking sonar, soundings, and a mud bottom worked for him.  Charts with 
notations "soundings from 1894" means be extra careful.  My handheld GPS 
didn't agree with charted positions of several reefs and islands by 
tenths of NM or more even after careful cross checking of chart and GPS 
reference datums.  My old lorans sometimes showed me a few hundred yards 
"on the beach" when comfortably at anchor.  In coastal waters we learned 
that Loran C positions were fairly repeatable and somewhat inaccurate. 
Offshore, I'd check now and then any electronic position with celestial, 
the ultimate backup/crosscheck and just for practice. (pretty hard to 
spoof, also).


One navigator showed me a factor that might have contributed to the 
Concordia sinking in addition to stupid.  The web update to the required 
electronic chart (all charts paper and electronic are updated monthly on 
commercial vessels) moved the obstruction marker buoy symbol and depth 
number images on top of each other, so one had to look very closely to 
see the depth number, which obviously was not enough for the Concordia.  
So, stupid crew plus a tiny slip of a cartographers mouse sank it.


I would also note that many recreational boaters, trust GPS to take them 
in pea soup fog to the dock waypoint or through the tight pass.  YMMV.


Grant KZ1W
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Re: [time-nuts] GPS Spoofing

[Fuqua, Bill L]

  The idea behind GPS spoofing is that one or several surface antennas and 
sources could be set up in such a way that they would produce believable 
position data that would take a vessel off course. The problem with this 
concept is that the person in charge of the GPS spoofing hardware has to know 
exactly where the vessel is at all times to start with and other vessels some 
distance away, and not very far from the target vessel would get contradicting 
signals from the virtual satellites. 
Software could be used to detect changes in position data that is inconsistent 
with present course and recent data. And in most cases there would be a period 
of very inconsistent signals from satellites and more obvious, signal 
strengths. 
Another way to limit spoofing is to use directional antennas that prevent 
reception from near horizon signals. Or detect low angle signals and sound the 
alarm or implement a means of ignoring those sources. 
The problem very high tech systems are often defeated by low tech solutions. 
Successful GPS spoofing would be very high tech. 
Many high tech systems that the government had developed in the past have been 
defeated by low tech methods. An example is the microwave system that is 
intended to turn back rioters by inducing burning pain. It was defeated by 
using thick wooden shields which absorbed the RF energy. 
Human resourcefulness and determination often defeats technology in low tech 
ways. And the more complex a system is the easier it is to defeat. “The more 
they overtake the plumbing the easier it is to stop up the drain.”
Most discussions have been about wireless spoofing. However, the most reliable 
way to do it would be an “inside job” where a device would be put on board and 
patched in the antenna lead. The correct GPS data would be received by the 
device and then it would produce a virtual constellation of satellites that 
would direct the vessel off course. However, the programmer would have to know 
the course that the pilot intended to take in the first place if his goal is to 
take the vessel to a different destination.  
73
Bill wa4lav
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Re: [time-nuts] GPS Spoofing

[David]

John, Omega did make it into the 'uP age' I briefly got involved in the 
80's and my first patent was for using DSPs and software radio for an 
Omega development . The key thing was Omega was genuinely world wide 
from a small chain of transmitters and one of the important users had to 
do their navigation while staying underwater for weeks on end, even 
Loran had limitations never mind satellite.


It might be the answer "the mystery Collins Ru" posting here, I remember 
similar items in airborne Omega receivers, the omega carrier frequencies 
were low but the receiver bandwidths were measured in mHz and phase 
error was critical hence the boxes I saw included similar references.


Its rather painful to see all the warnings about GPS made 30 years ago 
having to be re addressed. I suspect Loran will not get a big revival, 
the important development since the '80s is probably cheap MEMS inertial 
measurement sensors that give a user a secure cheap independent 
accessory to integrate with GPS etc. Its not an alternative but a rather 
useful thing to merge into a system to help deal with spoofing or other 
signal loss, this page from Analog Devices shows prices and performance:


http://www.analog.com/en/mems-sensors/mems-inertial-measurement-units/products/index.html#iSensor_MEMS_Inertial_Measurement_Units

There are other opportunistic navigation systems that try (tried?) other 
approaches such as Peter Duffett-Smith's Cursor system which I think is 
now in the hands of CSR.


Regards
David



--

Message: 1
Date: Sun, 28 Jul 2013 15:24:30 -0700 (PDT)
From: "J. Forster" 

Subject: Re: [time-nuts] GPS Spoofing

I'm not so convinced about this:

"OMEGA was the primary means of radio navigation, world wide, from 1976 to
1997. ."

There was LORAN-C, after all.

And Omega was a CW, phase difference system, LORAN a pulse system.

AFAIK, Omega never really made it into the uP age; LORAN certainly did.

-John

===




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Re: [time-nuts] GPS Spoofing

[Poul-Henning Kamp]

In message <51f62b9d.5020...@braw.co.uk>, David writes:

>having to be re addressed. I suspect Loran will not get a big revival, 
>the important development since the '80s is probably cheap MEMS inertial 
>measurement sensors [...]

They're fine for playing with robots and steering rockets, but they're
absolutely useless for navigating planes, cars and automobiles, as they
drift tens of degrees per hour.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] GPS Spoofing

[David]

They're fine for playing with robots and steering rockets, but they're
absolutely useless for navigating planes, cars and automobiles, as they
drift tens of degrees per hour.

No. I said deliberately said "secure cheap independent accessory to 
integrate with GPS" if you are proposing something different then thats 
a different answer  but when it comes to "navigating planes, cars and 
automobiles" they are  here now and will become more obvious with time, 
I carefully said integration with GPS etc, that's the key.


David





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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

On Jul 29, 2013, at 4:45 AM, David  wrote:

> John, Omega did make it into the 'uP age' I briefly got involved in the 80's 
> and my first patent was for using DSPs and software radio for an Omega 
> development . The key thing was Omega was genuinely world wide from a small 
> chain of transmitters and one of the important users had to do their 
> navigation while staying underwater for weeks on end, even Loran had 
> limitations never mind satellite.

Loran-C was always a poor bet for navigating in the southern hemisphere.

> 
> It might be the answer "the mystery Collins Ru" posting here, I remember 
> similar items in airborne Omega receivers, the omega carrier frequencies were 
> low but the receiver bandwidths were measured in mHz and phase error was 
> critical hence the boxes I saw included similar references.
> 
> Its rather painful to see all the warnings about GPS made 30 years ago having 
> to be re addressed.

Indeed, all of this was gone over *many* times in the 80's. Those involved were 
*very* knowledgeable about all of these systems and their weaknesses. None of 
the decisions we are living with were made in a vacuum or without a lot of 
discussion.

Bob

> I suspect Loran will not get a big revival, the important development since 
> the '80s is probably cheap MEMS inertial measurement sensors that give a user 
> a secure cheap independent accessory to integrate with GPS etc. Its not an 
> alternative but a rather useful thing to merge into a system to help deal 
> with spoofing or other signal loss, this page from Analog Devices shows 
> prices and performance:
> 
> http://www.analog.com/en/mems-sensors/mems-inertial-measurement-units/products/index.html#iSensor_MEMS_Inertial_Measurement_Units
> 
> There are other opportunistic navigation systems that try (tried?) other 
> approaches such as Peter Duffett-Smith's Cursor system which I think is now 
> in the hands of CSR.
> 
> Regards
> David
> 
> 
>> ----------
>> 
>> Message: 1
>> Date: Sun, 28 Jul 2013 15:24:30 -0700 (PDT)
>> From: "J. Forster" 
>> 
>> Subject: Re: [time-nuts] GPS Spoofing
>> 
>> I'm not so convinced about this:
>> 
>> "OMEGA was the primary means of radio navigation, world wide, from 1976 to
>> 1997. ."
>> 
>> There was LORAN-C, after all.
>> 
>> And Omega was a CW, phase difference system, LORAN a pulse system.
>> 
>> AFAIK, Omega never really made it into the uP age; LORAN certainly did.
>> 
>> -John
>> 
>> ===
>> 
> 
> 
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Re: [time-nuts] GPS Spoofing

[J. Forster]

Well, OK, but I never saw a small, <$500 box that could be put on pleasure
boats, etc. and directly read out Lat/Long. Such things were available at
the local boating store for LORAN.

-John

==.




> John, Omega did make it into the 'uP age' I briefly got involved in the
> 80's and my first patent was for using DSPs and software radio for an
> Omega development . The key thing was Omega was genuinely world wide
> from a small chain of transmitters and one of the important users had to
> do their navigation while staying underwater for weeks on end, even
> Loran had limitations never mind satellite.
>
> It might be the answer "the mystery Collins Ru" posting here, I remember
> similar items in airborne Omega receivers, the omega carrier frequencies
> were low but the receiver bandwidths were measured in mHz and phase
> error was critical hence the boxes I saw included similar references.
>
> Its rather painful to see all the warnings about GPS made 30 years ago
> having to be re addressed. I suspect Loran will not get a big revival,
> the important development since the '80s is probably cheap MEMS inertial
> measurement sensors that give a user a secure cheap independent
> accessory to integrate with GPS etc. Its not an alternative but a rather
> useful thing to merge into a system to help deal with spoofing or other
> signal loss, this page from Analog Devices shows prices and performance:
>
> http://www.analog.com/en/mems-sensors/mems-inertial-measurement-units/products/index.html#iSensor_MEMS_Inertial_Measurement_Units
>
> There are other opportunistic navigation systems that try (tried?) other
> approaches such as Peter Duffett-Smith's Cursor system which I think is
> now in the hands of CSR.
>
> Regards
> David
>
>
>> ----------
>>
>> Message: 1
>> Date: Sun, 28 Jul 2013 15:24:30 -0700 (PDT)
>> From: "J. Forster" 
>>
>> Subject: Re: [time-nuts] GPS Spoofing
>>
>> I'm not so convinced about this:
>>
>> "OMEGA was the primary means of radio navigation, world wide, from 1976
>> to
>> 1997. ."
>>
>> There was LORAN-C, after all.
>>
>> And Omega was a CW, phase difference system, LORAN a pulse system.
>>
>> AFAIK, Omega never really made it into the uP age; LORAN certainly did.
>>
>> -John
>>
>> ===
>>
>
>
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Re: [time-nuts] GPS Spoofing

[J. Forster]

>From what I've been told privately and off the record, the vacuum was not
filled with political gas.

YMMV,

-John

=



[snip]
> Indeed, all of this was gone over *many* times in the 80's. Those involved
> were *very* knowledgeable about all of these systems and their weaknesses.
> None of the decisions we are living with were made in a vacuum or without
> a lot of discussion.
>
> Bob


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Re: [time-nuts] GPS Spoofing

[Scott McGrath]

We've been discussing both GNSS denial/spoofing vs Loran denial/spoofing and 
the relative difficulty of doing same to determine which system is most 
survivable

That being said the penalty for using the truck stop/spy shop GPS should be in 
the hundreds of thousands per day and carry serious jail time. As most of them 
are easily capable of affecting a square mile as if you look at the specs from 
their Chinese suppliers.  

If you want to keep your boss from finding that you spent more than allocated 
time eating lunch just wrap the antenna in Al foil



Sent from my iPhone

On Jul 29, 2013, at 1:12 AM, "Fuqua, Bill L"  wrote:

>  The idea behind GPS spoofing is that one or several surface antennas and 
> sources could be set up in such a way that they would produce believable 
> position data that would take a vessel off course. The problem with this 
> concept is that the person in charge of the GPS spoofing hardware has to know 
> exactly where the vessel is at all times to start with and other vessels some 
> distance away, and not very far from the target vessel would get 
> contradicting signals from the virtual satellites. 
> Software could be used to detect changes in position data that is 
> inconsistent with present course and recent data. And in most cases there 
> would be a period of very inconsistent signals from satellites and more 
> obvious, signal strengths. 
> Another way to limit spoofing is to use directional antennas that prevent 
> reception from near horizon signals. Or detect low angle signals and sound 
> the alarm or implement a means of ignoring those sources. 
> The problem very high tech systems are often defeated by low tech solutions. 
> Successful GPS spoofing would be very high tech. 
> Many high tech systems that the government had developed in the past have 
> been defeated by low tech methods. An example is the microwave system that is 
> intended to turn back rioters by inducing burning pain. It was defeated by 
> using thick wooden shields which absorbed the RF energy. 
> Human resourcefulness and determination often defeats technology in low tech 
> ways. And the more complex a system is the easier it is to defeat. “The more 
> they overtake the plumbing the easier it is to stop up the drain.”
> Most discussions have been about wireless spoofing. However, the most 
> reliable way to do it would be an “inside job” where a device would be put on 
> board and patched in the antenna lead. The correct GPS data would be received 
> by the device and then it would produce a virtual constellation of satellites 
> that would direct the vessel off course. However, the programmer would have 
> to know the course that the pilot intended to take in the first place if his 
> goal is to 
> take the vessel to a different destination.  
> 73
> Bill wa4lav
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Re: [time-nuts] GPS Spoofing

[J. Forster]

Prohibition never works. It's been tried with booze, drugs, pay sex, and
guns, at least, and failed every time.

If people want something badly enough, they will get it.

Ask yourself, is the collateral damage worth it?

MMV,

-John

=





> We've been discussing both GNSS denial/spoofing vs Loran denial/spoofing
> and the relative difficulty of doing same to determine which system is
> most survivable
>
> That being said the penalty for using the truck stop/spy shop GPS should
> be in the hundreds of thousands per day and carry serious jail time. As
> most of them are easily capable of affecting a square mile as if you look
> at the specs from their Chinese suppliers.
>
> If you want to keep your boss from finding that you spent more than
> allocated time eating lunch just wrap the antenna in Al foil
>
>
>
> Sent from my iPhone
>
> On Jul 29, 2013, at 1:12 AM, "Fuqua, Bill L"  wrote:
>
>>  The idea behind GPS spoofing is that one or several surface antennas
>> and sources could be set up in such a way that they would produce
>> believable position data that would take a vessel off course. The
>> problem with this concept is that the person in charge of the GPS
>> spoofing hardware has to know exactly where the vessel is at all times
>> to start with and other vessels some distance away, and not very far
>> from the target vessel would get contradicting signals from the virtual
>> satellites.
>> Software could be used to detect changes in position data that is
>> inconsistent with present course and recent data. And in most cases
>> there would be a period of very inconsistent signals from satellites and
>> more obvious, signal strengths.
>> Another way to limit spoofing is to use directional antennas that
>> prevent reception from near horizon signals. Or detect low angle signals
>> and sound the alarm or implement a means of ignoring those sources.
>> The problem very high tech systems are often defeated by low tech
>> solutions. Successful GPS spoofing would be very high tech.
>> Many high tech systems that the government had developed in the past
>> have been defeated by low tech methods. An example is the microwave
>> system that is intended to turn back rioters by inducing burning pain.
>> It was defeated by using thick wooden shields which absorbed the RF
>> energy.
>> Human resourcefulness and determination often defeats technology in low
>> tech ways. And the more complex a system is the easier it is to defeat.
>> “The more they overtake the plumbing the easier it is to stop up the
>> drain.”
>> Most discussions have been about wireless spoofing. However, the most
>> reliable way to do it would be an “inside job” where a device would
>> be put on board and patched in the antenna lead. The correct GPS data
>> would be received by the device and then it would produce a virtual
>> constellation of satellites that would direct the vessel off course.
>> However, the programmer would have to know the course that the pilot
>> intended to take in the first place if his goal is to
>> take the vessel to a different destination.
>> 73
>> Bill wa4lav
>> ___
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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Omega is a lane based system. You need to know your start point to keep track 
of where you are. That made small boat units impractical. Pre-GPS Loran was 
pretty much the only small boat option. Once cheap GPS came out, Loran sales in 
that market went to zero. 

Bob

On Jul 29, 2013, at 8:57 AM, J. Forster  wrote:

> Well, OK, but I never saw a small, <$500 box that could be put on pleasure
> boats, etc. and directly read out Lat/Long. Such things were available at
> the local boating store for LORAN.
> 
> -John
> 
> ==.
> 
> 
> 
> 
>> John, Omega did make it into the 'uP age' I briefly got involved in the
>> 80's and my first patent was for using DSPs and software radio for an
>> Omega development . The key thing was Omega was genuinely world wide
>> from a small chain of transmitters and one of the important users had to
>> do their navigation while staying underwater for weeks on end, even
>> Loran had limitations never mind satellite.
>> 
>> It might be the answer "the mystery Collins Ru" posting here, I remember
>> similar items in airborne Omega receivers, the omega carrier frequencies
>> were low but the receiver bandwidths were measured in mHz and phase
>> error was critical hence the boxes I saw included similar references.
>> 
>> Its rather painful to see all the warnings about GPS made 30 years ago
>> having to be re addressed. I suspect Loran will not get a big revival,
>> the important development since the '80s is probably cheap MEMS inertial
>> measurement sensors that give a user a secure cheap independent
>> accessory to integrate with GPS etc. Its not an alternative but a rather
>> useful thing to merge into a system to help deal with spoofing or other
>> signal loss, this page from Analog Devices shows prices and performance:
>> 
>> http://www.analog.com/en/mems-sensors/mems-inertial-measurement-units/products/index.html#iSensor_MEMS_Inertial_Measurement_Units
>> 
>> There are other opportunistic navigation systems that try (tried?) other
>> approaches such as Peter Duffett-Smith's Cursor system which I think is
>> now in the hands of CSR.
>> 
>> Regards
>> David
>> 
>> 
>>> --
>>> 
>>> Message: 1
>>> Date: Sun, 28 Jul 2013 15:24:30 -0700 (PDT)
>>> From: "J. Forster" 
>>> 
>>> Subject: Re: [time-nuts] GPS Spoofing
>>> 
>>> I'm not so convinced about this:
>>> 
>>> "OMEGA was the primary means of radio navigation, world wide, from 1976
>>> to
>>> 1997. ."
>>> 
>>> There was LORAN-C, after all.
>>> 
>>> And Omega was a CW, phase difference system, LORAN a pulse system.
>>> 
>>> AFAIK, Omega never really made it into the uP age; LORAN certainly did.
>>> 
>>> -John
>>> 
>>> ===
>>> 
>> 
>> 
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>> 
> 
> 
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Re: [time-nuts] GPS Spoofing

[Scott McGrath]

I'm not for prohibiting ownership of as that would break a lot of companies 
test programs including the one I work for as we have a spirent in a cage to 
test LTE systems. And every avionics shop would be out of business

But if the FCC catches someone USING a jammer to  access to GPS i dont have a 
problem with FCC throwing book at miscreant 

There is a big difference between unintentional interference and actively 
disrupting the only publically available precision navigation and time source

Keep a jammer up long enough near a cell tower and you can bring tower down as 
well.  Where do you think all those Tbolts come from.  And because of GPS you 
no longer need a Cs reference in the CO for clock as you have all those flying 
clocks up there

Sent from my iPhone

On Jul 29, 2013, at 12:23 PM, "J. Forster"  wrote:

> Prohibition never works. It's been tried with booze, drugs, pay sex, and
> guns, at least, and failed every time.
> 
> If people want something badly enough, they will get it.
> 
> Ask yourself, is the collateral damage worth it?
> 
> MMV,
> 
> -John
> 
> =
> 
> 
> 
> 
> 
>> We've been discussing both GNSS denial/spoofing vs Loran denial/spoofing
>> and the relative difficulty of doing same to determine which system is
>> most survivable
>> 
>> That being said the penalty for using the truck stop/spy shop GPS should
>> be in the hundreds of thousands per day and carry serious jail time. As
>> most of them are easily capable of affecting a square mile as if you look
>> at the specs from their Chinese suppliers.
>> 
>> If you want to keep your boss from finding that you spent more than
>> allocated time eating lunch just wrap the antenna in Al foil
>> 
>> 
>> 
>> Sent from my iPhone
>> 
>> On Jul 29, 2013, at 1:12 AM, "Fuqua, Bill L"  wrote:
>> 
>>> The idea behind GPS spoofing is that one or several surface antennas
>>> and sources could be set up in such a way that they would produce
>>> believable position data that would take a vessel off course. The
>>> problem with this concept is that the person in charge of the GPS
>>> spoofing hardware has to know exactly where the vessel is at all times
>>> to start with and other vessels some distance away, and not very far
>>> from the target vessel would get contradicting signals from the virtual
>>> satellites.
>>> Software could be used to detect changes in position data that is
>>> inconsistent with present course and recent data. And in most cases
>>> there would be a period of very inconsistent signals from satellites and
>>> more obvious, signal strengths.
>>> Another way to limit spoofing is to use directional antennas that
>>> prevent reception from near horizon signals. Or detect low angle signals
>>> and sound the alarm or implement a means of ignoring those sources.
>>> The problem very high tech systems are often defeated by low tech
>>> solutions. Successful GPS spoofing would be very high tech.
>>> Many high tech systems that the government had developed in the past
>>> have been defeated by low tech methods. An example is the microwave
>>> system that is intended to turn back rioters by inducing burning pain.
>>> It was defeated by using thick wooden shields which absorbed the RF
>>> energy.
>>> Human resourcefulness and determination often defeats technology in low
>>> tech ways. And the more complex a system is the easier it is to defeat.
>>> “The more they overtake the plumbing the easier it is to stop up the
>>> drain.”
>>> Most discussions have been about wireless spoofing. However, the most
>>> reliable way to do it would be an “inside job” where a device would
>>> be put on board and patched in the antenna lead. The correct GPS data
>>> would be received by the device and then it would produce a virtual
>>> constellation of satellites that would direct the vessel off course.
>>> However, the programmer would have to know the course that the pilot
>>> intended to take in the first place if his goal is to
>>> take the vessel to a different destination.
>>> 73
>>> Bill wa4lav
>>> ___
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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Slow down a moment ….

If the cell tower is CDMA then yes GPS will have an impact on it.  If it's TDMA 
/ GSM - not so much.

If the cell tower is working properly, it'll go into holdover for at least 24 
hours (and probably a *lot* more) before there is an issue.

If the cell tower has an operator with >= 1/4 of a brain, they will have 
somebody out there within 4 to 8 hours. By 12 hours everything will be swapped 
out and checked (probably a lot less).

At some point the guy may / will / should notice that the GPS in his car is 
going nuts.

Well before 24 hours with no fix, it gets bumped up. Next tier *will* check 
their GPS. In comes the FCC (and likely others).

If the jammer isn't found in 24 - 96 hours, in comes a backup mobile tower. 

If that's jammed as well, you loose cell service from one provider over a 
relatively small area. This happens all the time. It happened here twice within 
the last month. 

If it happens enough people switch to another provider.

The world does not end because I can't text my buddies *right now*….



The TBolt's come from an early E-911 system. They don't do it that way anymore. 
The current thinking is that you put an aided GPS in all the phones. We have 
them because the system went out of service. 

---

Bob 


On Jul 29, 2013, at 8:33 PM, Scott McGrath  wrote:

> I'm not for prohibiting ownership of as that would break a lot of companies 
> test programs including the one I work for as we have a spirent in a cage to 
> test LTE systems. And every avionics shop would be out of business
> 
> But if the FCC catches someone USING a jammer to  access to GPS i dont have a 
> problem with FCC throwing book at miscreant 
> 
> There is a big difference between unintentional interference and actively 
> disrupting the only publically available precision navigation and time source
> 
> Keep a jammer up long enough near a cell tower and you can bring tower down 
> as well.  Where do you think all those Tbolts come from.  And because of GPS 
> you no longer need a Cs reference in the CO for clock as you have all those 
> flying clocks up there
> 
> Sent from my iPhone
> 
> On Jul 29, 2013, at 12:23 PM, "J. Forster"  wrote:
> 
>> Prohibition never works. It's been tried with booze, drugs, pay sex, and
>> guns, at least, and failed every time.
>> 
>> If people want something badly enough, they will get it.
>> 
>> Ask yourself, is the collateral damage worth it?
>> 
>> MMV,
>> 
>> -John
>> 
>> =
>> 
>> 
>> 
>> 
>> 
>>> We've been discussing both GNSS denial/spoofing vs Loran denial/spoofing
>>> and the relative difficulty of doing same to determine which system is
>>> most survivable
>>> 
>>> That being said the penalty for using the truck stop/spy shop GPS should
>>> be in the hundreds of thousands per day and carry serious jail time. As
>>> most of them are easily capable of affecting a square mile as if you look
>>> at the specs from their Chinese suppliers.
>>> 
>>> If you want to keep your boss from finding that you spent more than
>>> allocated time eating lunch just wrap the antenna in Al foil
>>> 
>>> 
>>> 
>>> Sent from my iPhone
>>> 
>>> On Jul 29, 2013, at 1:12 AM, "Fuqua, Bill L"  wrote:
>>> 
 The idea behind GPS spoofing is that one or several surface antennas
 and sources could be set up in such a way that they would produce
 believable position data that would take a vessel off course. The
 problem with this concept is that the person in charge of the GPS
 spoofing hardware has to know exactly where the vessel is at all times
 to start with and other vessels some distance away, and not very far
 from the target vessel would get contradicting signals from the virtual
 satellites.
 Software could be used to detect changes in position data that is
 inconsistent with present course and recent data. And in most cases
 there would be a period of very inconsistent signals from satellites and
 more obvious, signal strengths.
 Another way to limit spoofing is to use directional antennas that
 prevent reception from near horizon signals. Or detect low angle signals
 and sound the alarm or implement a means of ignoring those sources.
 The problem very high tech systems are often defeated by low tech
 solutions. Successful GPS spoofing would be very high tech.
 Many high tech systems that the government had developed in the past
 have been defeated by low tech methods. An example is the microwave
 system that is intended to turn back rioters by inducing burning pain.
 It was defeated by using thick wooden shields which absorbed the RF
 energy.
 Human resourcefulness and determination often defeats technology in low
 tech ways. And the more complex a system is the easier it is to defeat.
 “The more they overtake the plumbing the easier it is to stop up the
 drain.”
 Most discussions have been about wireless spoofing. Howe

Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

Missed one…

On Jul 29, 2013, at 8:33 PM, Scott McGrath  wrote:

> I'm not for prohibiting ownership of as that would break a lot of companies 
> test programs including the one I work for as we have a spirent in a cage to 
> test LTE systems. And every avionics shop would be out of business
> 
> But if the FCC catches someone USING a jammer to  access to GPS i dont have a 
> problem with FCC throwing book at miscreant 
> 
> There is a big difference between unintentional interference and actively 
> disrupting the only publically available precision navigation and time source
> 
> Keep a jammer up long enough near a cell tower and you can bring tower down 
> as well.  Where do you think all those Tbolts come from.  And because of GPS 
> you no longer need a Cs reference in the CO for clock as you have all those 
> flying clocks up there

The whole Stratum 1, 2, 3 world is still alive and well in the CO world. In 
normal operation, everybody swims on time from upstream. You need:

1) GPS denial (hasn't happened yet, so rare)
2) CO with Stratum 1 as a possibility (rare, but they do exist).
3) CO looses sync  over it's land lines (again, rare)

The same holdover / maintenance  process works there as well. Things have to be 
out for a while (days) to have much of an impact. Even then the main issue is a 
few more clicks on the line. The downstream stuff world will track the CO for a 
*long* time before anything truly looses lock. 

Bob

> 
> Sent from my iPhone
> 
> On Jul 29, 2013, at 12:23 PM, "J. Forster"  wrote:
> 
>> Prohibition never works. It's been tried with booze, drugs, pay sex, and
>> guns, at least, and failed every time.
>> 
>> If people want something badly enough, they will get it.
>> 
>> Ask yourself, is the collateral damage worth it?
>> 
>> MMV,
>> 
>> -John
>> 
>> =
>> 
>> 
>> 
>> 
>> 
>>> We've been discussing both GNSS denial/spoofing vs Loran denial/spoofing
>>> and the relative difficulty of doing same to determine which system is
>>> most survivable
>>> 
>>> That being said the penalty for using the truck stop/spy shop GPS should
>>> be in the hundreds of thousands per day and carry serious jail time. As
>>> most of them are easily capable of affecting a square mile as if you look
>>> at the specs from their Chinese suppliers.
>>> 
>>> If you want to keep your boss from finding that you spent more than
>>> allocated time eating lunch just wrap the antenna in Al foil
>>> 
>>> 
>>> 
>>> Sent from my iPhone
>>> 
>>> On Jul 29, 2013, at 1:12 AM, "Fuqua, Bill L"  wrote:
>>> 
 The idea behind GPS spoofing is that one or several surface antennas
 and sources could be set up in such a way that they would produce
 believable position data that would take a vessel off course. The
 problem with this concept is that the person in charge of the GPS
 spoofing hardware has to know exactly where the vessel is at all times
 to start with and other vessels some distance away, and not very far
 from the target vessel would get contradicting signals from the virtual
 satellites.
 Software could be used to detect changes in position data that is
 inconsistent with present course and recent data. And in most cases
 there would be a period of very inconsistent signals from satellites and
 more obvious, signal strengths.
 Another way to limit spoofing is to use directional antennas that
 prevent reception from near horizon signals. Or detect low angle signals
 and sound the alarm or implement a means of ignoring those sources.
 The problem very high tech systems are often defeated by low tech
 solutions. Successful GPS spoofing would be very high tech.
 Many high tech systems that the government had developed in the past
 have been defeated by low tech methods. An example is the microwave
 system that is intended to turn back rioters by inducing burning pain.
 It was defeated by using thick wooden shields which absorbed the RF
 energy.
 Human resourcefulness and determination often defeats technology in low
 tech ways. And the more complex a system is the easier it is to defeat.
 “The more they overtake the plumbing the easier it is to stop up the
 drain.”
 Most discussions have been about wireless spoofing. However, the most
 reliable way to do it would be an “inside job” where a device would
 be put on board and patched in the antenna lead. The correct GPS data
 would be received by the device and then it would produce a virtual
 constellation of satellites that would direct the vessel off course.
 However, the programmer would have to know the course that the pilot
 intended to take in the first place if his goal is to
 take the vessel to a different destination.
 73
 Bill wa4lav
 ___
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Re: [time-nuts] GPS Spoofing

[Max Robinson]

Bill quoted.

“The more they overtake the plumbing the easier it is to stop up the drain.”

Scotty in Star Trek The search for Spock.

Regards.

Max.  K 4 O DS.

Email: m...@maxsmusicplace.com

Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Woodworking site 
http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html

Music site: http://www.maxsmusicplace.com

To subscribe to the fun with transistors group send an email to.
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- Original Message - 
From: "Fuqua, Bill L" 

To: 
Sent: Monday, July 29, 2013 12:12 AM
Subject: Re: [time-nuts] GPS Spoofing


 The idea behind GPS spoofing is that one or several surface antennas and 
sources could be set up in such a way that they would produce believable 
position data that would take a vessel off course. The problem with this 
concept is that the person in charge of the GPS spoofing hardware has to 
know exactly where the vessel is at all times to start with and other 
vessels some distance away, and not very far from the target vessel would 
get contradicting signals from the virtual satellites.
Software could be used to detect changes in position data that is 
inconsistent with present course and recent data. And in most cases there 
would be a period of very inconsistent signals from satellites and more 
obvious, signal strengths.
Another way to limit spoofing is to use directional antennas that prevent 
reception from near horizon signals. Or detect low angle signals and sound 
the alarm or implement a means of ignoring those sources.
The problem very high tech systems are often defeated by low tech solutions. 
Successful GPS spoofing would be very high tech.
Many high tech systems that the government had developed in the past have 
been defeated by low tech methods. An example is the microwave system that 
is intended to turn back rioters by inducing burning pain. It was defeated 
by using thick wooden shields which absorbed the RF energy.
Human resourcefulness and determination often defeats technology in low tech 
ways. And the more complex a system is the easier it is to defeat. “The more 
they overtake the plumbing the easier it is to stop up the drain.”
Most discussions have been about wireless spoofing. However, the most 
reliable way to do it would be an “inside job” where a device would be put 
on board and patched in the antenna lead. The correct GPS data would be 
received by the device and then it would produce a virtual constellation of 
satellites that would direct the vessel off course. However, the programmer 
would have to know the course that the pilot intended to take in the first 
place if his goal is to

take the vessel to a different destination.
73
Bill wa4lav
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Re: [time-nuts] GPS Spoofing

[Magnus Danielson]

On 27/07/13 13:19, Brian Alsop wrote:

If you know your LORAN has a 1/4 mile accuracy then you stay 1/2 mile
away from bad things.

The trouble with GPS is that it is so good, people don't use common
sense and give obstacles a wide berth.


The published civilian precision of GPS isn't much better than LORAN-C, 
but it gives much better performance now for many reasons, including 
many birds in view and SA turn-off.


You do have hit the point, normally GPS works so darn good for most 
usage, that you perceive it to always be there, out of flaws. It's now 
with GPS receivers in phones that people start to learn that you can be 
in radio-shadow...


GPS is a good service when it is there, but when it isn't quite there or 
gone, you need to have a backup-plan, and know when to execute it.

LORAN-C is a good back-up plan.

Cheers,
Magnus
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Re: [time-nuts] GPS Spoofing

[Bob Camp]

Hi

On Jul 31, 2013, at 6:47 AM, Magnus Danielson  
wrote:

> On 27/07/13 13:19, Brian Alsop wrote:
>> If you know your LORAN has a 1/4 mile accuracy then you stay 1/2 mile
>> away from bad things.
>> 
>> The trouble with GPS is that it is so good, people don't use common
>> sense and give obstacles a wide berth.
> 
> The published civilian precision of GPS isn't much better than LORAN-C, but 
> it gives much better performance now for many reasons, including many birds 
> in view and SA turn-off.
> 
> You do have hit the point, normally GPS works so darn good for most usage, 
> that you perceive it to always be there, out of flaws. It's now with GPS 
> receivers in phones that people start to learn that you can be in 
> radio-shadow...
> 
> GPS is a good service when it is there, but when it isn't quite there or 
> gone, you need to have a backup-plan, and know when to execute it.
> LORAN-C is a good back-up plan.

Except that in practice Loran-C was much less reliable than GPS. Up comes a 
flag that says "GPS & Loran don't agree". The vast majority of the time it'll 
be Loran that's wrong. Very quickly a normal person will default right back to 
the GPS.

Bob

> 
> Cheers,
> Magnus
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Re: [time-nuts] GPS Spoofing

[Magnus Danielson]

On 28/07/13 19:16, Bob Camp wrote:

Hi

If we are now down to a truck sized / house sized area, I'd claim that Loran-C 
is dead simple to jam. That's what the truck stop gizmos are aimed at.


There where truck-sized spare transmitters to be utilized in failure/war 
as I recall it.


The main reason LORAN-C was "hard" to jam wide-area, was that it would 
require a large antenna for good transmission properties, and that would 
be easy to detect and take out. DFing would also be possible, as such 
work has already been done in LORAN-C (recall the search of the false 
transmitter of the coast of Texas).


For smaller area, you can use a smaller antenna with worse performance 
but still achieve the goal.


Cheers,
Magnus
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Re: [time-nuts] GPS Spoofing- oops

[J. Forster]

Oops:

>From what I've been told privately and off the record, the vacuum was not
a vacuum, but was filled with political gas.

Sorry,

-John

==



> From what I've been told privately and off the record, the vacuum was not
> filled with political gas.
>
> YMMV,
>
> -John
>
> =
>
>
>
> [snip]
>> Indeed, all of this was gone over *many* times in the 80's. Those
>> involved
>> were *very* knowledgeable about all of these systems and their
>> weaknesses.
>> None of the decisions we are living with were made in a vacuum or
>> without
>> a lot of discussion.
>>
>> Bob
>
>
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>


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