Beidou Triple-frequency Cycle Slip Detection and Repair Method Based on Adaptive Threshold
During the cycle slip detection,the detection values of single-frequency Doppler integration method are noisy,and the fixed threshold can't reflect the noise of actual detection values in dynamic environment.To solve these problems,a Beidou triple-frequency Doppler integration combination method was designed,and an adaptive threshold model was constructed based on the sliding window and elevation angle information.The geometry-free phase combination method was combined to detect the cycle slip of the Beidou triple-frequency data.In order to solve the problem that triple-frequency Doppler integration combination method had insensitive cycle-slips,the space search method was used to solve the combinations of cycle slips,and the cycle slips were checked and repaired according to the principle of minimum 1-norm.The results show that,in dynamic environment,the adaptive threshold reduces misjudgments in cycle slip detection of medium and low elevation satellites.All combinations of cycle slips including one cycle can be detected and repaired correctly with this method.