【摘 要】
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In view of the problem ofthe long term variation of code multipath error (called code multipath bias) in the IGSO and MEO satellite observable in Beidou satellite navigation system(BDS),code multipath
【机 构】
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Xi an Institute of High Technology, 710025 Xian, China
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In view of the problem ofthe long term variation of code multipath error (called code multipath bias) in the IGSO and MEO satellite observable in Beidou satellite navigation system(BDS),code multipath biasof BDS is analyzed using iGMAS data of multiple earth stations.In addition,the GPS and BDS multipath error variation is analyzed comparatively.The results show that the variation of BDS multipath error is related to the elevation angle,satellite orbit type and carrier frequency,but independent with the location of the receivers.And for the carrier frequency B1,B2,and B3,the code multipath biasfor MEO satellite is1.66m,1.05m and 0.53mrespectively,andfor IGSO satellite,the code multipath bias is 0.65m,0.44m and 0.31m accordingly,which are smaller than that reported by earlier papers (exclude the B1 one for MEO satellite).Especially,for IGSO at frequency B2and B3,the code multipath bias is smaller than half of that reported earlier.At the same time,in order to reduce the multipath bias,a two-order polynomial fitting algorithm is proposed in this paper.The results show that: compared with the results of piecewise linear model with 10 correction parameters,the two-order polynomial correction algorithm with 3 correction parameterscan correct the multipath error and reduce the RMS of the multipath error more effectively.The two-order polynomial model in this paper is more convenient considering broadcasting the correction information to the users.
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