I just checked Google Earth and the elevation of your office is 5260', only
about 24' off of your GPS estimate if that is your location.
Michael
On Wed, Jun 8, 2016 at 1:33 PM, Van Horn, David <
david.vanh...@backcountryaccess.com> wrote:
>
> I have just installed a Thunderbolt here to get our ti
osition the answer
should be with +/- 10'.
Michael Perrett
On Wed, Jun 8, 2016 at 1:33 PM, Van Horn, David <
david.vanh...@backcountryaccess.com> wrote:
>
> I have just installed a Thunderbolt here to get our time and frequency
> equipment all on the same page.
> As I w
Since, I assume, you are most interested in time/frequency I recommend you
use the position that each device self determined. To verify the 10 Mhz
output it is easy to compare one against the other. If you don't have a
frequency meter with enough digits, just use a 'scope syncing on one and
see if
I think the following might be relief to all the traffic regards "bad GPS"
ref January 26th.
http://gpsworld.com/world-dodges-gps-bullet/
Michael / K7HIL
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Alex, Brek - the Doppler effect is primarily an effect of the ionosphere
moving. A 24 hour measurement of WWV on 20 Mhz shows as much as +/- 800 mHz
movement, all due to Doppler. Note that if you run the measurement over
several days at the same time of year the measured frequency will strongly
cor
Since your antennas have a lot of gain I assume they are active and require
a DC voltage to the LNA. Does the XL-DC provide that voltage (sometime you
have to select active or passive antenna)?
Michael / K7HIL
On Wed, Feb 25, 2015 at 12:35 PM, Doug Ronald wrote:
> I'm hoping someone can shed som
Chris,
I disagree only with your statement "as a GPS user you'd never know".
As stated in one of John's references:
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 broad
As one responsible for the architecture and design of many military vehicle
GPS based navigation systems I will "un-simplify" my previous email. The
GPS solution (position or Doppler) is always made at the center of the GPS
antenna; that's where the lines of intersection (3D) from the individual
sa
The ability to correct the position depends on the receiver. Some receivers
have a correction known as the lever arm correction. This is the vector
difference between the antenna centroid and there is also a variable to
enter the cable length. Between these two corrections the receiver time and
pos
If you are going to plug the unit re time nuts, how about a price break for
said group?
Michael
On Fri, Apr 4, 2014 at 3:39 PM, wrote:
> Hello everyone,
>
> sorry for the plug, but we just announced a new $568 complete GPSDO
> reference kit.
>
> This unit is a tiny desktop unit with 10m antenna
Wow, if 1 second in 300 million years is correct, that's around 1 E-16th.
M
On Thu, Apr 3, 2014 at 2:51 PM, Edesio Costa e Silva <
time-n...@tardis.net.br> wrote:
> Full story at
> http://www.nist.gov/pml/div688/nist-f2-atomic-clock-040314.cfm
>
> Edésio
> ___
I recently bought a La Crosse, See at ebay item 360752857574, that quickly
synced up to WWVB and, at least to my ability to mark a time tick, been
within the second of WWV. Total cost was $43.
Michael / K7HIL
On Wed, Feb 19, 2014 at 4:52 PM, Richard (Rick) Karlquist <
rich...@karlquist.com> wrote
According to the manual (in several places):
*It is normal operation for the fan in the Counter to continue to run after
the Counter is*
*placed in Standby mode. Power to the timebase is continuous to maintain
long term*
*measurement reliability, and the fan helps maintain timebase temperature
sta
http://gpsworld.com/tag/l2c/
On Fri, Jan 17, 2014 at 10:11 AM, Jim Lux wrote:
> On 1/17/14 8:43 AM, Michael Perrett wrote:
>
>> Magnus, I believe that he is referencing the the new L2 C/A code, which is
>> not protected. Reference
>> http://www.gps.gov/systems/gps/mo
Magnus, I believe that he is referencing the the new L2 C/A code, which is
not protected. Reference
http://www.gps.gov/systems/gps/modernization/civilsignals/
Michael / K7HIL
On Thu, Jan 16, 2014 at 2:04 PM, Magnus Danielson <
mag...@rubidium.dyndns.org> wrote:
> On 16/01/14 20:29, Hal Murray w
It is the receiver, not the satellites, that are WASS enabled.
The WASS differentials are used to correct the ionosphere path lengths.
Michael K7HIL- Sent from my Samsung S4
On Jan 7, 2014 6:07 PM, "Bob Camp" wrote:
> Hi
>
> The WAAS sat’s are (in general) going to be long path sat’s. That will
>
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,
There are multiple variables that effect the "minimum" number of fixes that
will yield a particular position accuracy (and hence a time accuracy when
using that position as truth).
(1) The ability of the antenna to see the entire sky. If a mountain, tall
building or tree is between you and a satel
Bob,
That is simply not accurate - if the solution rate is 1/second, then all
parameters are solved in that time frame. There are 4 indpendent variables
and minimal processing power is required to solve all four equations.
Although I am not very familiar with commercial receivers, that is what
happ
Welcome aboard.
Michel / K7HIL
On Sun, Dec 2, 2012 at 1:06 PM, Erich Heine wrote:
> Hi everyone.
>
> I just wanted to introduce myself to the list. My name is Erich Heine, I'm
> a researcher at the University of Illinois. I am a programmer attached to a
> couple of projects, but the one relevan
*UNLESS *the subject changes. I get so sick of the title having nothing to
do with the message. Sometimes a thread will completely change and have 20
or more "answers". Personally I would prefer a new thread if the subject
changes.
IMHO,
Michael / K7HIL
On Fri, Nov 2, 2012 at 7:20 AM, David C. Pa
John,
Coherent reproduction of the spread PRN standard positioning signal (SPS)
signal gives ~30dB of A/J protection, the GPS signal level, as received at
the GPS receiver is on the order of -160 dBW (L1-CA). If the jammer outputs
half a Watt, and is anywhere nearby, the receiver will not maintain
First - I realize 95% of the folks reading this are well aware of what I am
going to say.
No matter how good your equipment (receiver/antenna) is, the short term
accuracy of GPS time is defined in *GLOBAL POSITIONING SYSTEM STANDARD
POSITIONING SERVICE PERFORMANCE STANDARD (2008)*. This document c
I have found Google translate does a pretty good job on translating manuals
- and it is free
Michael
On Thu, Aug 23, 2012 at 6:40 AM, Richard Parrish wrote:
> The seller of the 'Russian' equipment said that the CCHB-74 frequency
> standard is a rubidium unit. Manual is in Russian but he can tra
Not for survey type accuracy (sub-meter, short measurement time).
The average (over a 48 hour period) was pretty good (about 1.5 meters,
RMS), but the reading over any 1 minute period can be off as much as 3-5
meters, satellite geometry dependent.
I Have two units with good antennas, mounted roug
Loran C absolute accuracy is between 0.1 and 0.25 miles (
http://msi.nga.mil/MSISiteContent/StaticFiles/NAV_PUBS/APN/Chapt-12.pdf)
but the repeatability is way better (from 60 to 300 feet, same ref).
When it was safe and fun to fly to Baja, Mexico I would record both ends of
the runway with my Nor
At least that is how the graphic is labeled :).
Per Enge (Author/Contributor of many GPS text books) has some good cartoons
on the current and future GPS Spectrum, and one power spectrum display, on:
http://www.navcanada.ca/ContentDefinitionFiles/IFIS/powerpoint/Session_2/GPS_Modernization_Enge.pd
Just be careful on overloading the front end of a GPS receiver. A typical
(what ever that is anymore) GPS receiver has about a maximum of a 15 dB
power bandwidth. If overloading occurs (minor), it might swamp the strong
signals. If you already have an active antenna the extra 12 dB of the
in-line a
navigators to indicate vertical direction, an example of this is when
using the north, east, down (NED) references in an inertial reference frame.
Michael
On Wed, Sep 14, 2011 at 2:59 PM, Magnus Danielson <
mag...@rubidium.dyndns.org> wrote:
> Michael,
>
> On 14/09/11 17:05, Michae
When GPS was first developed (Late 70's) the DATUM used was the World
Geodetic System, 1972 (WGS-72). The next release was indeed in 1984
(WGS-84). The early GPS receivers had over 200 datums stored in permanent
memory. In its most basic form a datum defines the center of the earth and
the equatio
First: Find the directory where LH resides (mine is D:\Program Files
(x86)\Heather).
Click the Windows start icon
In the search windw type "command"
Click on the "command prompt.
Change to the LH directory (I am using mine, you will have to find your own
location).
enter- "D: (return)"This
I went a different route - I bought a multiport serial card (PCIE RS232C)
and have a dedicated, unique, serial port for the Tbolt. I put it on COM 15,
which did not even exist prior to the addition and have had no conflicts
since. Just added /15 to the .exe command line.
PC: Home made I7-875 CPU O
Stan;
I had the same problem. The "correct" fix (i.e. permanent) is to buy a
RS232C plug-in board for your PC. This allows the port choice to remain
fixed. With the USB to serial adapter the port can change every time you
reboot the computer. I purchased a board with 8 db9 connector 'dongles',
this
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