Wavelet analysis: multipath mitigation from GPS carrier phase observation / Mohd Rijal Shukri

Multipath mitigation techniques using wavelet decomposition is proposed for extracting or modeling multipath from Global Positioning System (GPS) carrier phase observations. Multipath is a phenomenon whereby satellite signals can arrive at the receiver via multiple paths, due to reflections from nearby objects such as trees, buildings, the ground, water surfaces, vehicles, etc. It can be reduced by choosing sites without multipath reflectors or by using choke-ring antennas to mitigate the reflected signal. Wavelet transform (WT) is a new tool for signal analysis that can provide simultaneously, time and frequency information of a signal sequence. The wavelet is of interest for the analysis of non- stationary signal such as GPS observations because it provides an alternative to classical Fourier Transform, which assumes stationary in signals. Double Differencing (DD) technique was use to detect the multipath effect.