From: Peter Vince <[EMAIL PROTECTED]> Subject: [time-nuts] Carrier phase tracking Date: Mon, 19 Feb 2007 16:30:04 +0000 Message-ID: <[EMAIL PROTECTED]>
> I sort of understand the idea of correlation in order to receive the > signals from several satellites all on the same frequency, but I > wonder if someone has a simple explanation of how the carrier phase > can be tracked when there are several carriers all at once? Does it > rely on the different Doppler-shifts making them distinguishable? No. GPS satellites have unique code sequences which have been chosen to be orthogonal, such that when one correlates the code of a satellite in one channel other visible sats will end up as suppressed noise, tracked or not. Also, in practice will all sats be at different frequencies due to their orbital positions and your position. They only briefly have the same frequency, but the code separation ensures that this is not a problem. Cheers, Magnus _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
