GNSS carrier phase integer equivariant estimator and its application in improving PPP performance

doi:10.11947/j.AGCS.2022.20210371

Abstract

Abstract: Precision point positioning (PPP) technology can provide global high-precision positioning results,but its main technical bottleneck lies in the long positioning convergence time.The carrier phase ambiguity fixing technology is one of the main means to speed up PPP convergence and improve positioning accuracy.The reliability of ambiguity fixing is particularly prominent in PPP positioning,because the quality of the ambiguity-float solutions depends on the quality of the server product,various factors such as the noise characteristics of the receiver and the observation environment,making high reliability PPP ambiguity fixing technology is still full of huge challenges.In order to ensure the reliability of PPP positioning,we introduce the best integer equivariant (BIE) estimator into the PPP ambiguity estimation process.The estimator improves the estimation accuracy of float ambiguities through multiple ambiguity-fixed solution weighting methods,thereby improving the PPP positioning accuracy and shortening the ambiguity convergence time.105 globally distributed MGEX stations are selected to verify the performance of BIE in PPP ambiguity estimation.Experimental results showed that compared with the ambiguity-fixed solutions,using BIE to estimate PPP ambiguities can further improve the positioning performance of east,north and up components of the coordinates,the convergence time of which can be shortened by 37%,28% and 31%,and the positioning accuracy of which is improved by 9%,8% and 3%,respectively.Furthermore,there are fewer glitches and steps in the positioning results derived from BIE-based PPP.

Key words: precise point positioning, best integer equivariant, ambiguity estimation, positioning performance

CLC Number:

P227

ZHOU Feng, YANG Yuze, WANG Lei, XU Tianhe. GNSS carrier phase integer equivariant estimator and its application in improving PPP performance[J]. Acta Geodaetica et Cartographica Sinica, 2022, 51(8): 1779-1786.

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