Data pretreatment in GPS baseline solution based on wavelet

摘要

This paper applies the wavelet to dispose the GPS observation data. If the GPS phasic observation data can be regard as time list to analysis, it shows a very lubricous curve. When the cycle-slip takes place, the velvet of the curve will be damaged. From the beginning epoch of the cycle-slip, the subsequent phasic observation data list take place equal cycle-slip. According to the principle which wavelet transforms detect signal, the GPS gross error or cycle slip can be regard as the break point of the signal to be identified. Because all kinds of the yawp and multipath have certain scope of frequency, the frequency characteristics of the useful signal and the yawp are different. The technology of Wavelet Transforms is used to detect the cycle-slip and the gross error in GPS phasic observation data. The filtering method based on wavelet transforms is very effective to improve the proportion of the signal and yawp which is the GPS double differential carrier observation data. The carrier observation data is filtered to eliminate the multipath and some yawp by wavelet and the observation data can be refined. This method has obvious function to decrease the scope of searching ambiguity and to improve the validity of the ambiguity, which can improve the precision of the baseline solution.