Cycle-slip Processing Of GNSS Tracking Data Exploiting New Frequencies And Signals

Cycle slips detection and repair has always been a key issue when carrier phase observations are used in high-precision GNSS applications.The modernization of the global positioning system(GPS),the advent of the European project Galileo along with China's Beidou are providing new signals and more frequencies,which could bring a potential refinement of the cycle slip detection and correction.In thesis,firstly a large variety of triple-frequency linear combinations are explored,and their capacities for a cycle slip detection and repair are thoroughly analyzed.Then we present a complete workflow for detecting and estimating the cycle slips based on several superior linear combinations.A Geometry free(GF)and Ionosphere free(IF)phase combination along with the Melbourne-Wubbena combinations are used jointly for a safe detection of cycle slips.Additionally a Geometry free(L1 minus L2)phase combination is provided optionally for identifying the insignificant cycle slip groups.After detecting the cycle slips,the size of them is estimated based a cascading method.Three types of linear combinations are constructed,which maintains the integer ambiguity of extra-wide-lane(EWL),wide-lane(WL)and narrow-lane(L1/E1/B1)respectively.Cycle slips on the combinations are determined sequentially in three cascaded steps.Once the three cascading cycle slips are fixed,the cycle slip at each of the three frequencies can be derived from the fixed ones.The proposed approach has been implemented into a Matlab program,and tested on tracking data of GPS Block IIF,Galileo,and BeiDou satellites collected in IGS stations.Results show that the proposed method is able to ensure a reliable detection of small cycle slips,with very few false results under a long-term data tests.Meanwhile,the estimation of cycle slip can achieve a high accuracy in the situation with minor ionospheric delay variation.