Slightly OT - GPS-Based Accurate Direction Finding
As a fair percentage of the discussion amongst the learned gentlemen on
this group involves GPS-based timing systems, I'd like to ask a non-time
related, but GPS-related question.
As part of microwave radio experimentation, often on windy hilltops, I
have a need to find direction very accurately. I have seen advertised
GPS-based Azimuth Pointing Systems such as this:
http://www.ascscientific.com/APS.html
However they are a little (lot) out of my budget range.
The system seems to work by taking the raw satellite phase information
from two separate GPS systems and crunching the data to come up with an
azimuth figure. Has anyone heard of a (Open Source?) program that could
be used to do these calculations?
Regards,
David Smith
The nominal accuracy is no better than using the sun as a compass.
Two GPS systems (say TBolts) have to be an amazingly great distance
apart to give a decent azimuth.
Apart from star observations, a gyrocompass is the tool of choice if
you want to add an azimuth to a GPS position.
Does anyone know how laser gyroscopes are developing?
cheers,
Neville Michie
On 26/08/2010, at 11:04 AM, David Smith wrote:
As a fair percentage of the discussion amongst the learned
gentlemen on this group involves GPS-based timing systems, I'd like
to ask a non-time related, but GPS-related question.
As part of microwave radio experimentation, often on windy
hilltops, I have a need to find direction very accurately. I have
seen advertised GPS-based Azimuth Pointing Systems such as this:
http://www.ascscientific.com/APS.html
However they are a little (lot) out of my budget range.
The system seems to work by taking the raw satellite phase
information from two separate GPS systems and crunching the data to
come up with an azimuth figure. Has anyone heard of a (Open
Source?) program that could be used to do these calculations?
Regards,
David Smith
time-nuts mailing list -- time-nuts@febo.com
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time-nuts
and follow the instructions there.
Hi
GPS is not very helpful for direction. It can be used as an accurate source of time and location to feed a solar or celestial direction estimate.
Bob
On Aug 25, 2010, at 9:04 PM, David Smith david@smithfamily.net.au wrote:
As a fair percentage of the discussion amongst the learned gentlemen on this group involves GPS-based timing systems, I'd like to ask a non-time related, but GPS-related question.
As part of microwave radio experimentation, often on windy hilltops, I have a need to find direction very accurately. I have seen advertised GPS-based Azimuth Pointing Systems such as this:
http://www.ascscientific.com/APS.html
However they are a little (lot) out of my budget range.
The system seems to work by taking the raw satellite phase information from two separate GPS systems and crunching the data to come up with an azimuth figure. Has anyone heard of a (Open Source?) program that could be used to do these calculations?
Regards,
David Smith
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and follow the instructions there.
Not cheap but VOR was used when I was flying.
http://en.wikipedia.org/wiki/VHF_omnidirectional_range
Stanley
----- Original Message ----
From: Bob Camp lists@rtty.us
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Wed, August 25, 2010 9:25:31 PM
Subject: Re: [time-nuts] Slightly OT - GPS-Based Accurate Direction Finding
Hi
GPS is not very helpful for direction. It can be used as an accurate source of
time and location to feed a solar or celestial direction estimate.
Bob
On Aug 25, 2010, at 9:04 PM, David Smith david@smithfamily.net.au wrote:
As a fair percentage of the discussion amongst the learned gentlemen on this
group involves GPS-based timing systems, I'd like to ask a non-time related, but
GPS-related question.
As part of microwave radio experimentation, often on windy hilltops, I have a
need to find direction very accurately. I have seen advertised GPS-based
Azimuth Pointing Systems such as this:
http://www.ascscientific.com/APS.html
However they are a little (lot) out of my budget range.
The system seems to work by taking the raw satellite phase information from two
separate GPS systems and crunching the data to come up with an azimuth figure.
Has anyone heard of a (Open Source?) program that could be used to do these
calculations?
Regards,
David Smith
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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google "Icom IC-A24"
Stanley
----- Original Message ----
From: Bob Camp lists@rtty.us
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Wed, August 25, 2010 9:25:31 PM
Subject: Re: [time-nuts] Slightly OT - GPS-Based Accurate Direction Finding
Hi
GPS is not very helpful for direction. It can be used as an accurate source of
time and location to feed a solar or celestial direction estimate.
Bob
On Aug 25, 2010, at 9:04 PM, David Smith david@smithfamily.net.au wrote:
As a fair percentage of the discussion amongst the learned gentlemen on this
group involves GPS-based timing systems, I'd like to ask a non-time related, but
GPS-related question.
As part of microwave radio experimentation, often on windy hilltops, I have a
need to find direction very accurately. I have seen advertised GPS-based
Azimuth Pointing Systems such as this:
http://www.ascscientific.com/APS.html
However they are a little (lot) out of my budget range.
The system seems to work by taking the raw satellite phase information from two
separate GPS systems and crunching the data to come up with an azimuth figure.
Has anyone heard of a (Open Source?) program that could be used to do these
calculations?
Regards,
David Smith
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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You still need to DF the VOR station to get your direction. guess any radio that
receives 108 to 117 MHz is good for that.
Stanley
On Aug 25, 2010, at 9:04 PM, David Smith david@smithfamily.net.au wrote:
As a fair percentage of the discussion amongst the learned gentlemen on this
group involves GPS-based timing systems, I'd like to ask a non-time related, but
GPS-related question.
As part of microwave radio experimentation, often on windy hilltops, I have a
need to find direction very accurately. I have seen advertised GPS-based
Azimuth Pointing Systems such as this:
http://www.ascscientific.com/APS.html
However they are a little (lot) out of my budget range.
The system seems to work by taking the raw satellite phase information from two
separate GPS systems and crunching the data to come up with an azimuth figure.
Has anyone heard of a (Open Source?) program that could be used to do these
calculations?
Regards,
David Smith
David,
Please see U.S. Patent # 5,777,578 "GPS Compass". I can send you a
copy if you cannot find it.
Bruce, WB9ANQ
--
Bruce Rahn
Wisdom has two parts:
- having a lot to say; and
- not saying it!
Hi David:
The military used to use a gyro compass to determine true north for
artillery. This need to be on the order of a mil. Now they use the Gun
Laying System that's part of the later PLGR GPS receivers and all of the
DAGR GPS receivers. There's two versions of this:
- uses a single GPS receiver and the other
- uses two GPS receivers. I have some data at:
http://www.prc68.com/I/DAGR.shtml#ZBL
The method is based on doing carrier phase post processing. Note you
don't need to tie into reference station data since only the distance
and bearing between two points is being determined.
Have Fun,
Brooke Clarke
http://www.PRC68.com
David Smith wrote:
As a fair percentage of the discussion amongst the learned gentlemen
on this group involves GPS-based timing systems, I'd like to ask a
non-time related, but GPS-related question.
As part of microwave radio experimentation, often on windy hilltops, I
have a need to find direction very accurately. I have seen advertised
GPS-based Azimuth Pointing Systems such as this:
http://www.ascscientific.com/APS.html
However they are a little (lot) out of my budget range.
The system seems to work by taking the raw satellite phase information
from two separate GPS systems and crunching the data to come up with
an azimuth figure. Has anyone heard of a (Open Source?) program that
could be used to do these calculations?
Regards,
David Smith
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.
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
Point of reference: A Garmin GPSMAP 60CSx will give you a GPS
azimuth once your speed in a straight line is above 10 MPH.
Not recommending it, just an observation.
Bill Hawkins
The nominal accuracy is no better than using the sun as a compass.
That is very wrong! With an open skyview, a 10 meter baseline, two decent
GPS receivers and antennas will outperform a northfinding gyro-solution
both in performance, measurement time and very much so in cost.
Two GPS systems (say TBolts) have to be an amazingly great distance
apart to give a decent azimuth.
Tbolts has no serial message giving carrier phase meassurements, but the
doppler measurements might be possible to use.
Apart from star observations, a gyrocompass is the tool of choice if
you want to add an azimuth to a GPS position.
If you are in an open environment, GPS is nowadays the best solution.
Does anyone know how laser gyroscopes are developing?
Laser gyroscopes - as in Ring Laser Gyroscopes or as in Fiber Optic
Gyroscopes?
cheers,
Neville Michie
On 26/08/2010, at 11:04 AM, David Smith wrote:
As a fair percentage of the discussion amongst the learned
gentlemen on this group involves GPS-based timing systems, I'd like
to ask a non-time related, but GPS-related question.
As part of microwave radio experimentation, often on windy
hilltops, I have a need to find direction very accurately. I have
seen advertised GPS-based Azimuth Pointing Systems such as this:
http://www.ascscientific.com/APS.html
However they are a little (lot) out of my budget range.
The system seems to work by taking the raw satellite phase
information from two separate GPS systems and crunching the data to
come up with an azimuth figure. Has anyone heard of a (Open
Source?) program that could be used to do these calculations?
Regards,
David Smith
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.