Re: [Paparazzi-devel] GPS precision

[Tom Kent]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

I've often wondered about this myself.  The one big potential hangup I
see is that if different receivers see different satellites, their error
could be substantially different.
Thus, if you have one vehicle in the air and it sees two satellites that
the ground station does not see, it could present a much more accurate
position.  However, since you're assuming the ground position is more
accurate, you would assume that the airborne one is off, and you would
actually ADD error back into your airborne one.

I think to make this work correctly, you need to determine the error
induced by each satellite, and send THAT information to the airborne
station.

Tom Kent

Ethan Arnold wrote:
> Dear List,
> 
> Has anyone ever tried laying 2 GPS receivers (same model) side by side and
> comparing the output over a reasonable period of time?
> 
> I noticed (with one receiver, under good reception) the measured GPS
> position slowly (under 1m/s) wanders around in an area of about 10-20m
> diameter. I was wondering if a second GPS receiver of the same model would
> show the same deviation at the same time. If this were the case, couldnt one
> use the stationary receiver as a reference point to correct the mobile GPS,
> as long as they are relatively close together (<1km), and hereby be able to
> detect the slow horizontal drifting of a helicopter, which otherwise couldnt
> be detected with only the on-board GPS receiver?
> 
> Regards,
> Ethan
> 
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFG3afBccZrtZUgfJARAuDQAJ9x9a8SANid7jVsNZ2aayUxkWUicACghOJF
KbZotUXMjOzpUefXq/QuGoo=
=f+Wq
-----END PGP SIGNATURE-----