Application Research Of GNSS Receiver Based On Carrier Phase Difference Method In Landslide Monitoring

The landslide disaster induced by slope deformation causes serious damage to the safety of local residents' lives and properties.The traditional monitoring technology has poor real-time performance and high labor costs.Real-time Kinematic(RTK)positioning technology based on carrier phase difference measurement method can provide centimeter-level positioning accuracy and has good real-time performance.Therefore,GNSS positioning technology utilizing RTK positioning technology has been widely used in landslide monitoring.However,in practical application,due to the complexity of the monitoring environment and the insufficient number of observable satellites,single system positioning technology appears the problem of low positioning accuracy or even unable to locate.In order to solve this problem,a GPS/BDS dual-band dual-mold RTK positioning technology was improved in this paper,and the algorithm was implemented by Matlab,and finally verified by experimental tests.In view of the need to further improve the positioning accuracy of landslide monitoring,a GPS/BDS dual-mode dual-frequency positioning model is constructed;on the basis of eliminating common errors through double-difference processing,a reasonable random model is constructed by means of height angle weighting to eliminate the multi-path effect.,atmospheric delay and other residuals;a robust adaptive Kalman filter method is proposed for parameter estimation.The adversarial adaptive Kalman filter model is corrected according to the weight matrix and the state discrepancy value,so as to obtain a more reliable parameter estimation value.In this paper,aiming at the shortcomings of the high-order difference method and the dual-frequency carrier phase difference method,this paper proposes a wavelet transform linear interpolation method.The method detects the occurrence of cycle slip and repairs the cycle slip;the integer ambiguity floating-point solution obtained in the parameter estimation is fixed by integer.In this paper,the LAMBDA algorithm with high fixed success rate is selected and implemented by the algorithm.The estimated value of the baseline vector is corrected by the subsequent integer ambiguity.On the basis of theoretical derivation,the GPS/BDS dual-mode dual-frequency RTK algorithm is implemented and verified by experiments.The experimental results show that the GPS/BDS dual-mode dual-frequency RTK positioning method has improved the success rate and positioning accuracy of the whole-cycle ambiguity fixation compared with the single-mode method,and the RMS value in the horizontal direction can reach 2.5 in the case of a short baseline.Within mm,the RMS in the elevation direction can reach within 4mm.The practical application was carried out on the side slope of the expressway in Xuwei section of Sichuan,and the real-time slope surface displacement of the slope was successfully obtained through the GNSS system using the algorithm introduced in this paper,and the early warning of the landslide event was successfully carried out.Practice has proved that the dual-mode positioning method studied in this paper improves the positioning performance,and has been verified in practical applications.