Evaluation of Wavelet Multipath Mitigation Technique in the Final Measurement Domain

Mohamed Elhabiby, Ahmed El-Ghazouly, Naser El-Sheimy

Abstract:	Multipath is highly dependent on satellite-reflectorantenna geometry, which usually causes rapid changes in phase multipath errors. The fact that multipath is dependent for each receiver makes it is impossible to eliminate through differencing techniques; for this multipath is considered one of the major sources of errors in differential GPS positioning. Recently, several approaches have been suggested to mitigate the impact of carrier phase multipath on GPS positioning results. In this paper, a new approach based on wavelet technique is introduced to remove the long wavelength carrier phase multipath error in the measurement domain. The presented wavelet-based trend extraction model is applied to GPS static baseline solutions. In order to mitigate multipath, GPS double difference observables are decomposed into two components based on the wavlet coefficients; details for high frequency and approximation for low frequency. Based on the fact that large errors are caused by the low frequency multipath, wavelet transform is used to separate the multipath errors at the high levels of decomposition. The separated wavelet coefficients (approximation or high-level decomposition coefficients) are truncated to zero before the reconstruction of the signal to extract the true double difference carrier phase residuals out of the low frequency multipath. This technique is being tested in the double difference domain and proved to give the highest multipath error reduction in this domain (Elhabiby et al. 2008). Systematic errors (mainly multipath) are isolated and extracted from GPS measurements in double difference domain using wavelet multi-resolution analysis by the application of this new trend detection methodology. In this paper, the efficiency of this technique will be evaluated in the coordinate’s domain.
Published in:	Proceedings of the 2009 International Technical Meeting of The Institute of Navigation January 26 - 28, 2009 Disney's Paradise Pier Hotel Anaheim, CA
Pages:	682 - 686
Cite this article:	Elhabiby, Mohamed, El-Ghazouly, Ahmed, El-Sheimy, Naser, "Evaluation of Wavelet Multipath Mitigation Technique in the Final Measurement Domain," Proceedings of the 2009 International Technical Meeting of The Institute of Navigation, Anaheim, CA, January 2009, pp. 682-686.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In