TITLE:
Multipath Error Analysis of COMPASS Triple Frequency Observations
AUTHORS:
Xuying Ma, Yunzhong Shen
KEYWORDS:
BeiDou-2 (COMPASS); Multipath; Wavelet Filtering; Single Point Positioning
JOURNAL NAME:
Positioning,
Vol.5 No.1,
January
28,
2014
ABSTRACT: The BeiDou-2 satellite navigation system
broadcasts triple frequency data. In this paper, the pseudorange multipath is extracted by
using the geometry-free and ionosphere-free combination of one pseudorange and
two phase measurements, and the phase multipath is extracted by
using triple frequency phase measurements, respectively. By using several days’ static observation data, we exact the noisy
pseudorange and phase multipath of three types of satellites, GEO, IGSO and MEO
satellites. Because of the low frequency characteristics of the multipath, the
low frequency wavelet filter is further used to recover the high-precision low
frequency multipath signals that are specified by their amplitudes, periods and
phases. The results show that the multipath periods are about 86160s, 86158s
and 46391s for GEO, IGSO and MEO satellites, respectively, which coincide with
that of the corresponding satellite orbits. Then we use the extracted multipath
signals to correct the pseudorange measurements in order to improve the
accuracy of point positioning. The positioning accuracy in East-West direction can be significantly improved by using the
multipath corrected pseudorange measurements, and in the other two directions
the positioning accuracy can also be improved to some extent.