Re: [time-nuts] Iridium source?

[Tom Van Baak]

Stu,

Thanks for the heads up. If you can leak anything from the upcoming paper 
please let us know.

Since you're an Iridium expert, would you be able to answer the question? The 
OP (John Todd) was asking about reception deep indoors, where GPS signals fail. 
In case you deleted it, the posting is here:
https://www.febo.com/pipermail/time-nuts/2015-October/094146.html

/tvb

- Original Message - 
From: "Stewart Cobb" 
To: 
Sent: Tuesday, October 06, 2015 6:51 PM
Subject: Re: [time-nuts] Iridium source?


> The use of Iridium satellite signals for timing, location, and
> position-based authentication is being commercialized by a startup called
> Satelles. The technology is known as Satelles Timing and Location, or STL.
> 
> 
> 
> Prototype STL timing systems are providing PPS with accuracy better than 1
> microsecond. This is expected to improve as the technology evolves.
> 
> Full disclosure: Satelles is my employer. We have submitted a paper on STL
> timing to PTTI 2016. Don't know yet whether it was accepted.
> 
> Cheers!
> --Stu

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Re: [time-nuts] Iridium source?

[Bob Bownes]

JT,

You say GPS isn't available 'often'. Can you define 'often'? As in not at
some locations, or as in GPS signal is only available now and then
temporally?

If the latter, any GPS timing unit with decent holdover should solve the
issue. If the former, well, you've gotten some replies on that.

Failing that, what are your drift tolerances? If you can manually set the
time, or get it 'close' with ntp & friends, a rubidium standard may jitter
a bit, but is pretty stable long term, even if you loose the NTP feed.
Cesium might drift a bit more...

iii

btw: Welcome to time-nuts. These folks are our kinda crazy.

On Mon, Oct 5, 2015 at 4:24 PM, John Todd  wrote:

>
> I’m working on a project that needs a good clocking source deep inside of
> noisy environments (data centers and the like.)  This can’t be
> network-based - it needs to be independent of the systems surrounding it,
> and GPS/GPS-like systems will often be unreachable.  I’ve read up a bit on
> Iridium - it appears that there is some mention of Boeing saying (see slide
> three in below link) that the Iridium LEO network can be used not just as a
> GPS assist, but as an actual timing source.  Their frequencies on the
> timing side seem to penetrate buildings better.  Before you say “Iridium
> doesn’t work indoors!”, this may not be the case with their timing signals.
>
> Has anyone actually used this method for obtaining high-precision time?
> If so, is it possible to do with something smaller/cheaper than the full
> Iridium chipset?  I think the Iridium Core 9523 is something like $1300,
> which puts it outside of consideration for the large deployment we’re
> looking at doing, and we don’t need the voice/data TX or RX components.
>
>
> https://transition.fcc.gov/bureaus/pshs/docs/summits/911%20Location%20Acuracy/Barry_Martin.pdf
>
> Apologies if this is not on-topic here or if there are obvious data that
> I’m missing - I’m a bit new to this niche of the world.  I can’t find any
> mention of this topic past 2012, and it’s sparse even at that.
>
> JT
>
> ---
> John Todd - Senior Technologist - jt...@pch.net - +1-415-831-3123
>
>
>
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Re: [time-nuts] Jackson Labs M12M Replacement Receiver

[Keith Loiselle]

If you are interested in purchasing you can do so directly through our ebay
listing here:
http://www.ebay.com/itm/-/181896123655

But, please contact me if you have any questions.

Thanks,
Keith



Keith

On Wed, Oct 7, 2015 at 7:14 AM, Keith Loiselle 
wrote:

> Hello everyone,
>
>
>
> Since there are many Fury GPSDO users here and many other users of the
> Motorola M12+ and M12M timing receivers, we wanted to introduce our new
> product which is an M12M compatible timing and navigation receiver that
> uses the latest uBlox M8T GNSS receiver, and is a one-to-one replacement
> for the aging, and hard to use Motorola/iLotus GPS receiver.
>
>
>
> This is kind of like a super M12M, with significant improvements in the
> 1PPS timing accuracy and stability, support for receiving two of any of the
> standard GNSS systems at any one time (GPS with SBAS, Glonass, QZSS,
> BeiDou, and soon Galileo), and true plug-and-play operation. It should work
> in pretty much most Motorola M12+ and M12M binary command applications.
>
>
>
> The unit is a form-fit-function compatible replacement for the M12M/M12+
> receivers, and has been qualified on the JLT Fury GPSDO as well as the
> Microsemi/Symmetricom XLI, and provides a massive upgrade in GNSS
> performance such as -167dBm tracking capability (think indoors reception
> may now be possible under certain circumstances), 72 channels capability
> for very fast cold-start and re-acquisition, and multi-GNSS support.
>
>
>
> It has some additional features such as:
>
> *   Two USB ports, one for easy SCPI control, one for full access to the
> uBlox commands for setup, as well as Carrier Phase, Almanac, and Ephemeris
> data. The unit can also be powered via the USB ports and used stand-alone
> sitting on a desk etc. There is no setup required though out-of-the-box,
> all setup is optional
>
> * 7-Segment LED status display and 5 additional status LEDs show GNSS
> status, fix status, signal strength, UTC time, and number of sats tracked
>
> * DIP switch for easy configuration of which GNSS systems should be
> enabled, Position Hold mode versus 3D Mobile mode, etc (these settings can
> be over-written by USB commands)
>
> * 1Hz to 10MHz+ buffered Synthesized (NCO) output that is
> frequency-locked to the GNSS system, and can be easily configured through
> the USB ports
>
> * Position Hold mode with Auto Survey, or full 3D mobile mode (selectable
> via USB, Motorola binary command, or via the DIP switch), supporting full
> Auto Kalman setup depending on vehicle dynamics (including auto-selection
> of Carrier Phase versus Doppler tracking etc)
>
> You can find out more in the User Manual and Spec Sheet available here:
>
>
> http://www.jackson-labs.com/assets/uploads/main/M12M_replacement_UserManual.pdf
>
>
> and
>
>
>
> http://www.jackson-labs.com/assets/uploads/main/M12M_replacement_Specsheet.pdf
>
> We are making this unit available to Time Nuts users for a special pricing
> of $185 per unit plus shipping. Pricing will revert to the list price of
> $220 at the end of this month. We are asking for anyone using the M12+ or
> M12M receivers in other than the Fury or XLI GPSDOs to help us test
> compatibility with those systems, and hope to have as many different
> products as possible tested out with your help.
>
>
>
> Please contact me OFFLINE(!) if you are interested in this unit.
>
> Thanks,
> Keith
>
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Re: [time-nuts] Rohde & Schwarz GPSDO

[Tom Knox]

What is interesting is I spent a little time on the Manufactures Web Site and 
could find no AD or PN specs.
So even if you can find the down converter antenna, you have no idea how well 
it will perform.
I imagine it has a something like an Oscilloquartz 8663. No doubt as with 
almost all RS products it will be very high build quality.
Cheers;
Thomas Knox



> From: rbenw...@verizon.net
> To: time-nuts@febo.com
> Date: Wed, 7 Oct 2015 22:41:11 -0400
> Subject: Re: [time-nuts] Rohde & Schwarz GPSDO
> 
> That's why you can run 300meters of RG-58!  This is the "missing"
> antenna/converter unit.
> 
> https://www.meinbergglobal.com/english/products/gps-antenna-converter.htm
> 
> Here is one, this time with the antenna:
> http://www.ebay.com/itm/Meinberg-ED170MP-GPS-Satellite-Disciplined-Atomic-Cl
> ock-10MHz-Oscillator-Antenna-/281560964740?hash=item418e575e84
> 
> Bob
> 
> >>> -Original Message-
> >>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Arthur
> >>> Dent
> >>> Sent: Wednesday, October 07, 2015 7:46 AM
> >>> To: time-nuts@febo.com
> >>> Subject: [time-nuts] Rohde & Schwarz GPSDO
> >>> 
> >>> I believe that like a lot of the Meinberg receivers that this uses a
> down
> >>> converter to give an IF frequency of
> >>> 35.4 MHz. If you don't have the converter that apparently isn't included
> with
> >>> the receiver you have a $300 paperweight.
> >>> You might want to check with the seller before bidding.
> >>> 
> >>> -Arthur
> >>> ___
> >>> 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.
> >>> -
> >>> No virus found in this message.
> >>> Checked by AVG - www.avg.com
> >>> Version: 2015.0.6140 / Virus Database: 4435/10749 - Release Date:
> >>> 10/03/15
> 
> ___
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> 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] KS-24361 REF-0 standalone

[Gregory Beat]

Bob -

 

Thank you for reference to the Synergy SSR-6T.

I talked to Gina at Synergy early today.

 

The Synergy SSR-6T is still available, but now at the regular price of
$68.20

 

The Synergy SSR-6T GPS receiver would likely not be appropriate for usage in
the Lucent KS-24361,

since it does not completely emulate the Motorola Oncore UT+ receiver.

Synergy does sell the adapter board for fitting M12 series receivers 

to the larger PCB form factor of the Motorola 8-channel receivers (VP, GT,
UT)

 

SO, full speed ahead with Dan's uBlox work on the REF0 !

 

greg

w9gb

===

Synergy Systems SSR-6T receiver (some information from CNS Systems / Rick
Hambly, W2GPS). 

 

The Synergy SSR-6T GPS receiver has the same footprint as the
Motorola/iLotus M12 series receiver. 

The SSR-6T has a uBlox LEA-6T receiver that operates in uBox NMEA or Binary
mode. 

A version of this board has a processor that permits emulation of M12 series
messages as well as
other modes. 

 

The CNS Systems TAC32 software changes to support SSR-6T:

Added the @@Wb message to switch the SSR-6T from M12 to uBlox message mode.

Added "@@Wc" to switch to the boot loader.

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Re: [time-nuts] KS-24361 REF-0 standalone

[Bob Camp]

Hi

The (likely) biggest issue with the M12 clone boards is that they are
12 channel. The report strings have more satellites in them than the 
old 8 channel boards did. That’s going to mess up the parsing algorithms 
if you want the REF-0 to work with all the data (record the sat info vs
ignore it). 

Bob

> On Oct 7, 2015, at 7:51 PM, Gregory Beat  wrote:
> 
> Bob -
> 
> 
> 
> Thank you for reference to the Synergy SSR-6T.
> 
> I talked to Gina at Synergy early today.
> 
> 
> 
> The Synergy SSR-6T is still available, but now at the regular price of
> $68.20
> 
> 
> 
> The Synergy SSR-6T GPS receiver would likely not be appropriate for usage in
> the Lucent KS-24361,
> 
> since it does not completely emulate the Motorola Oncore UT+ receiver.
> 
> Synergy does sell the adapter board for fitting M12 series receivers 
> 
> to the larger PCB form factor of the Motorola 8-channel receivers (VP, GT,
> UT)
> 
> 
> 
> SO, full speed ahead with Dan's uBlox work on the REF0 !
> 
> 
> 
> greg
> 
> w9gb
> 
> ===
> 
> Synergy Systems SSR-6T receiver (some information from CNS Systems / Rick
> Hambly, W2GPS). 
> 
> 
> 
> The Synergy SSR-6T GPS receiver has the same footprint as the
> Motorola/iLotus M12 series receiver. 
> 
> The SSR-6T has a uBlox LEA-6T receiver that operates in uBox NMEA or Binary
> mode. 
> 
> A version of this board has a processor that permits emulation of M12 series
> messages as well as
> other modes. 
> 
> 
> 
> The CNS Systems TAC32 software changes to support SSR-6T:
> 
> Added the @@Wb message to switch the SSR-6T from M12 to uBlox message mode.
> 
> Added "@@Wc" to switch to the boot loader.
> 
> ___
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> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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Re: [time-nuts] Rohde & Schwarz GPSDO

[Azelio Boriani]

Without the necessary antenna/downconverter.

On Wed, Oct 7, 2015 at 4:06 AM, Bob Benward  wrote:
>
>
> If anyone is interested, a Rohde & Schwarz GPSDO:
>
>
>
>
>
> Rohde & Schwarz GPS RECEIVER ED170MP MEINBERG 2105.5504.00
>
>
>
> http://www.ebay.com/itm/262081245211?_trksid=p2055119.m1438.l2649
> =STRK%3AMEBIDX%3AIT
>
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[time-nuts] Rohde & Schwarz GPSDO

[Bob Benward]

 

If anyone is interested, a Rohde & Schwarz GPSDO:

 

 

Rohde & Schwarz GPS RECEIVER ED170MP MEINBERG 2105.5504.00

 

http://www.ebay.com/itm/262081245211?_trksid=p2055119.m1438.l2649
=STRK%3AMEBIDX%3AIT

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[time-nuts] Rohde & Schwarz GPSDO

[Arthur Dent]

I believe that like a lot of the Meinberg receivers that
this uses a down converter to give an IF frequency of
35.4 MHz. If you don't have the converter that apparently
isn't included with the receiver you have a $300 paperweight.
You might want to check with the seller before bidding.

-Arthur
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Re: [time-nuts] Iridium source?

[Jim Lux]

On 10/7/15 1:16 AM, Tom Van Baak wrote:

Stu,

Thanks for the heads up. If you can leak anything from the upcoming paper 
please let us know.

Since you're an Iridium expert, would you be able to answer the question? The 
OP (John Todd) was asking about reception deep indoors, where GPS signals fail. 
In case you deleted it, the posting is here:
https://www.febo.com/pipermail/time-nuts/2015-October/094146.html




I would worry about the varying propagation time through the building. 
Over the past couple years, I've been propagating 3 GHz signals through 
a variety of buildings, piles of rubble, and so forth.


There's two effects I can think of with respect to timing:
a) the propagation path is highly scattered, and there is a lot of 
fading (on a scale comparable to wavelengths.. so if the satellite is 
moving at 7 km/s, and the wavelength is 20 cm, you're going to get fades 
at 35 kHz).. More to the point, the phase shift is wildly fluctuating in 
the short term, but pretty stable in the long term average sense.


b) The "average" path length is going to change as the satellite to 
ground terminal angle changes, because you're going through more or less 
of the building (unless the building happens to be a big symmetrical 
radome that you are in the center of)


Dense rubble has a propagation velocity of about 50-70% of free space. 
Buildings are pretty close to free space: the effect is one of bouncing 
around in an indirect path, rather than going through walls, although 
there's some of both effects.


In any case, at 1 foot/nanosecond in free space, going through, say, 3-4 
feet of construction material at 0.70 Velocity is going to add a 
nanosecond to your time delay.


The attached is a modeled gaussian pulse propagating through 5-7 meters 
of mixed rubble (I don't recall the exact geometry.. the rubble pile is 
5x5x3 meters in this model, and I think the transmitter was at one 
corner and the receiver is buried near the opposite corner)



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[time-nuts] SDG Electronics GPSDO - Mod/Hack/Build

[Gregory Beat]

Steve Gardner is an Electronics and Firmware Engineer in the UK.
Earlier this year (2015), Steve started a Blog with YouTube videos to share 
some of his knowledge and personal projects, which he hopes to grow both to 
engage others in the hobby and also to help complete stalled projects.

He is about 3/4-way through a DIY GPSDO Build using a surplus Symmetricom 
Time & Frequency Receiver.  He has 3 videos on YouTube walking through project 
steps (and Nick Watney style learning steps).
https://sdgelectronics.co.uk/10mhz-frequency-reference-gpsdo/

Steve also had a surplus Trimble SVeeSix receiver (earlier project thus year), 
that he eas a but stuck on what he was observing (1995 date).
Over weekend, I sent him links to scanned Trimble manual (KO4BB) and industry 
article on 1024 week rollover issues (since he appears to be unaware of that 
issue).

greg
w9gb

Sent from iPad Air
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[time-nuts] Jackson Labs M12M Replacement Receiver

[Keith Loiselle]

Hello everyone,



Since there are many Fury GPSDO users here and many other users of the
Motorola M12+ and M12M timing receivers, we wanted to introduce our new
product which is an M12M compatible timing and navigation receiver that
uses the latest uBlox M8T GNSS receiver, and is a one-to-one replacement
for the aging, and hard to use Motorola/iLotus GPS receiver.



This is kind of like a super M12M, with significant improvements in the
1PPS timing accuracy and stability, support for receiving two of any of the
standard GNSS systems at any one time (GPS with SBAS, Glonass, QZSS,
BeiDou, and soon Galileo), and true plug-and-play operation. It should work
in pretty much most Motorola M12+ and M12M binary command applications.



The unit is a form-fit-function compatible replacement for the M12M/M12+
receivers, and has been qualified on the JLT Fury GPSDO as well as the
Microsemi/Symmetricom XLI, and provides a massive upgrade in GNSS
performance such as -167dBm tracking capability (think indoors reception
may now be possible under certain circumstances), 72 channels capability
for very fast cold-start and re-acquisition, and multi-GNSS support.



It has some additional features such as:

*   Two USB ports, one for easy SCPI control, one for full access to the
uBlox commands for setup, as well as Carrier Phase, Almanac, and Ephemeris
data. The unit can also be powered via the USB ports and used stand-alone
sitting on a desk etc. There is no setup required though out-of-the-box,
all setup is optional

* 7-Segment LED status display and 5 additional status LEDs show GNSS
status, fix status, signal strength, UTC time, and number of sats tracked

* DIP switch for easy configuration of which GNSS systems should be
enabled, Position Hold mode versus 3D Mobile mode, etc (these settings can
be over-written by USB commands)

* 1Hz to 10MHz+ buffered Synthesized (NCO) output that is frequency-locked
to the GNSS system, and can be easily configured through the USB ports

* Position Hold mode with Auto Survey, or full 3D mobile mode (selectable
via USB, Motorola binary command, or via the DIP switch), supporting full
Auto Kalman setup depending on vehicle dynamics (including auto-selection
of Carrier Phase versus Doppler tracking etc)

You can find out more in the User Manual and Spec Sheet available here:

http://www.jackson-labs.com/assets/uploads/main/M12M_replacement_UserManual.pdf


and


http://www.jackson-labs.com/assets/uploads/main/M12M_replacement_Specsheet.pdf

We are making this unit available to Time Nuts users for a special pricing
of $185 per unit plus shipping. Pricing will revert to the list price of
$220 at the end of this month. We are asking for anyone using the M12+ or
M12M receivers in other than the Fury or XLI GPSDOs to help us test
compatibility with those systems, and hope to have as many different
products as possible tested out with your help.



Please contact me OFFLINE(!) if you are interested in this unit.

Thanks,
Keith
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