Detection And Repair Of Cycle Slip Of GPS Based On Wavelet Analysis

GPS cycle slip detection and repair is one important problem for GPS carrier phases measurements. The occurrence of cycle slip will bring severe influence to calculating integer ambiguity, the result of the survey is difficult to reach the forecast request of the precision. So many new techniques and methods are applied to the detection and repair of cycle slip of GPS. wavelet analysis is an available and feasible tool to dealing with problem of GPS cycle slip. In the decades, wavelet analysis achieved a quick development. It can analyze any details of signals which can be observed, because the trait that it has good local character and auto-regulated density in time domain sampling according to the different components of the signals. Wavelet analysis is the functional analysis, Fourier analysis, digital analysis, and nowadays, as a new tool to transforming signals, it is applied to many fields of science research and engineering technology, such as digital signal filtering, signal separate and pickup signal character.The article applies theory of wavelets to the detection of cycle slip after discussing the theory of the wavelet in detail. When we concern carrier phases, if they are regarded as the signal about the time sequence, we can find that carrier phases are recorded continuously. As a function about time, carrier phases show smooth curve to us, but this smooth will be destroy as soon as cycle slip appears. Basing wavelet's character, we harness the multi-resolution analysis of the discrete transformation of the wavelet to decompose double difference carrier phases, then special frequency components will be pickup via band-pass filter. The different wavelets have different characters, and have the different abilities in detecting and repairing cycle slip. After the popular wavelets are compared through the instances, this article not only gains good results but also demonstrates the best wavelets used for detecting and repairing cycle slip in the terms of the theory and the practice. This job is meaningful for the scholars in this field.