On Tue, 2008-11-11 at 10:28 -0800, Lux, James P wrote: > > A GPS receiver actually solves for the state vector of the receiver > (including the local clock error) using the raw observables from the tracking > loop (code phase). The nav equations calculate (apparent) range and range > rate from the known state vector of each satellite and the (estimated) state > vector of the receiver. Range rate is the doppler. > > The 1.xxx Megachip/second C/A code is 1023 bits long, so the classical > approach is to step the receiver through all possible phases of the code, > integrating at each one to see if it can detect the signal. If your > integration time is, say, 10 milliseconds, it takes 10 seconds to step > through them all. Once the signal is detected, the PN tracking loop tracks > that signal.
You also need to check different doppler bins. 500Hz bins are a classic choice. -- Björn _______________________________________________ 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.
