On 10/08/2010 07:27 PM, J. Forster wrote:
I've been half following this thread and can't make out the reason for a less than hemispheric antenna pattern. GPS needs several birds to lock up, and if you look at a single bird, Dopplar will make the signal useless as a frequency reference.
If you target the WAAS, EGNOS or SBAS birds you have significant less doppler since they sit on geostationary orbit. However, since these orbits is not perfect circular but slightly elliptic, so a 24 h pattern evolves. Just squaring up, as proposed earlier in the thread, will suffer from these shifts. Also, ionospheric and tropospheric delays also plays in, but the point of these birds is to provide improved predictions so a good receiver should be able to handle it. You also rely on the time of the base-station, but that is obvious I hope.
Cheers, Magnus _______________________________________________ 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.
