Precision Measurement Technology Based On Satellite Navigation RTK

In recent years,the global satellite navigation and positioning system has continued to develop.With the continuous improvement of wide-area and local-area enhancement systems,the accuracy of positioning has also improved,reaching centimeters to millimeters,making it applicable to the field of precision measurement and break through the limitation of the measurement space in the previous precision measurement,and expand the precision measurement from the local space to the larger space work scene.This paper studies the key technology of RTK(real-time kinematic)carrier phase differential precise measurement in satellite navigation and positioning.The determination of integer ambiguity is a key problem when RTK technology is applied to precision measurement.It mainly conducts detailed research on three parts: the search for the integer ambiguity in RTK technology,the design and implementation of RTK applied to a new landslide monitoring system,and the processing of RTK monitoring data.Firstly,aiming at the low efficiency of traditional ant colony algorithm in searching the integer ambiguity of GNSS,due to the lack of initial pheromone,an improved hybrid algorithm of particle swarm optimization and ant colony algorithm is proposed to search the integer ambiguity of GNSS.In the initial stage of the search,use the advantage of the improved particle swarm optimization algorithm to perform a rough search to obtain a sub-optimal solution,adjust the initial distribution of the pheromone of the improved ant colony algorithm with this solution,and finally use the improved ant colony algorithm to perform a fine search of the integer ambiguity.The results show that the improved hybrid algorithm can converge to the optimal solution faster than the single algorithm,the search efficiency is significantly better than the LAMBDA algorithm,and the baseline accuracy of the solution can be controlled within 3mm,and the effectiveness and reliability are very good.verification.Based on this,the application of RTK in practical engineering is studied.Secondly,for the traditional GNSS-RTK landslide monitoring system with the increase of observation nodes,the problem of low cost performance and the missing alarm caused by the simultaneous displacement of the base station and the observation station.The new system is a double-layer landslide monitoring system based on GNSS-RTK technology.On the basis of the traditional landslide monitoring system,a micro-grid observation system has been added to some important node areas,which has been improved from“point”monitoring to micro-area“surface”monitoring,and realized deformation data collection based on GNSS-RTK technology and data transmission based on H800 digital radio and 4G Technology.The test results show that the data transmission is reliable and efficient,and the measurement accuracy of the system can reach millimeter level,which meets the requirements of landslide monitoring,and can meet the needs of different environments by adjusting the observation node density and baseline length in the micro area of the observation station.Finally,in view of the problem of low accuracy when GNSS-RTK technology is applied to deformation monitoring,which makes effective monitoring impossible,a data preprocessing and abnormal state identification method based on deformation data is proposed.First,the improved Laida criterion is used to eliminate gross errors,then wavelet denoising is used,and finally the Shewhart mean control chart is constructed according to the abnormal deformation data model.The results show that the improved Laida criterion can eliminate real-time gross errors of the measured deformation data,the wavelet denoising set according to the optimal wavelet coefficients can effectively improve the accuracy of the deformation data,and the Shewhart mean control chart combined with the improved Laida criterion can realize the effective monitoring of deformation data.Through the above research,RTK technology is finally applied to the actual landslide monitoring,and the monitoring accuracy can reach millimeter level.