Multipath Error Analysis of COMPASS Triple Frequency Observations

Abstract

The BeiDou-2 satellite navigation systembroadcasts triple frequency data. In this paper, the pseudorange mul tipath is extracted byusing the geometry-free and ionosphere-free combination of one pseudorange andtwo phase measurements, and the phase multipath is extracted byusing triple frequency phase measurements, respectively. By using several days ’ static observation data, we exact the noisypseudorange and phase multipath of three types of satellites, GEO, IGSO and MEOsatellites. Because of the low frequency characteristics of the multipath, thelow frequency wavelet filter is further used to recover the high-precision lowfrequency multipath signals that are specified by their amplitudes, periods andphases. The results show that the multipath periods are about 86160s, 86158sand 46391s for GEO, IGSO and MEO satellites, respectively, which coincide withthat of the corresponding satellite orbits. Then we use the extracted multipathsignals to correct the pseudorange measurements in order to improve theaccuracy of point positioning. The positioning accuracy in East-West di rection can be significantly improved by using themultipath corrected pseudorange measurements, and in the other two directionsthe positioning accuracy can also be improved to some extent .