Estimation of Multipath Range Error for Detection of Erroneous Satellites

T. Iwase, N. Suzuki, Y. Watanabe

Abstract:	In integrated systems for accurate positioning which consist of GNSS, INS and other sensors, the GNSS positioning accuracy has a decisive influence on the performance of the entire system and thus is very important. However, GNSS usually exhibits poor positioning results in urban canyon environments due to pseudorange measurement errors caused by multipath creation, which leads to performance degradation of the entire positioning system. For this reason, in order to maintain the accuracy of an integrated positioning system, it is necessary to determine when the GNSS positioning is accurate and which satellites can have their pseudorange measured accurately without multipath errors. Thus, the objective of our work is to detect the multipath errors in the satellite signals and exclude these signals to improve the positioning accuracy of GNSS and consequently the integrated positioning system, especially in an urban canyon environment. One of the previous technologies for tackling this problem is RAIM, which checks the residual of the least square and identifies the suspicious satellites. However, it presumes a Gaussian measurement error which is more common in an open-sky environment than in the urban canyon environment. On the other hand, our proposed method tries to estimate the size of the multipath error directly and use the estimated error to weight satellite signals and improve the positioning accuracy. The proposed method was tested with a low-cost GNSS receiver mounted on a test vehicle in a test drive in Nagoya, Japan, which is a typical urban canyon environment. With this experimental data, the accuracy of the multipath error estimation and of the improved positioning are discussed.
Published in:	Proceedings of the 23rd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2010) September 21 - 24, 2010 Oregon Convention Center, Portland, Oregon Portland, OR
Pages:	2228 - 2235
Cite this article:	Iwase, T., Suzuki, N., Watanabe, Y., "Estimation of Multipath Range Error for Detection of Erroneous Satellites," Proceedings of the 23rd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2010), Portland, OR, September 2010, pp. 2228-2235.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In