Peak tracking/measurement compensation multipath mitigation technique

Multipath remains a major source of positioning error for high precision GPS applications such as aircraft approach and landing and surveying. Signal processing methods offer a flexible approach to mitigate multipath by special processing carried out within the receiver. We combine a correlation function “peak tracking” algorithm with an open-loop correction to the pseudorange (PR) measurement to achieve greatly improved multipath bias error reduction over standard code tracking methods. The open-loop correction is determined from a multipath indicator (MPI) function, which is, in turn, a special function of the individual correlator values. The new algorithm was tested in a GPS receiver and its performance is demonstrated with data collected from both live and GPS satellite simulator signals