Slope Deformation Monitoring Technology Based On Beidou Real-time Kinematic Data

The stability of highway slopes affects the safety of life and property of road construction workers and road users greatly.As the Beidou satellite navigation system is about to complete the global networking,the application of the Beidou satellite navigation system to highway slope monitoring has made a lot of progress,but the main direction of research is still directed at the Beidou satellite navigation system itself,and it has not done too much at the application level.In view of the above problems,this paper takes the collected Beidou real-time kinematic data as the research object,combining the collected high-precision kinematic data with the data denoising algorithm to further improve the data accuracy.After applying it to the stability monitoring of highway slopes,it can provide reliable data support for highway slope construction and management.The main research content and results are as follows:1.The factors affecting the Beidou kinematic positioning accuracy are analyzed from the two aspects of external natural environment and electromagnetic environment.By analyzing the influence of various external natural environmental factors such as weather factors,geographical environment and geological conditions on the positioning accuracy,it is pointed out how to reasonably find the monitoring points according to the natural environment when performing slope monitoring.In addition,by analyzing the influence of the electromagnetic environment such as radio transmission equipment and electromagnetic interference on the positioning accuracy,it is proposed that when selecting the installation location of the equipment,the distance between the antennas of the radio station should be reasonably determined according to the height of the antenna of the radio station and the surrounding obstacles.At the same time,pay attention to avoid the radio transmission source close to the frequency of the Beidou navigation satellite system,and maintain the distance from the high-voltage transmission line.After comprehensively considering the external natural environment and electromagnetic environment,set the receiver parameters reasonably.Select a satellite with a smaller PDOP value and a smaller GDOP value for monitoring,and the number of common-view satellites should be greater than 4 to ensure the quantity and quality of data collection at monitoring points.2.For the collected real-time kinematic data,the outliers in the data are identified and eliminated by using the Pau Ta criterion,the Chauvenet criterion,and the Box-plot method.By comparing the processing results of the three methods,the Pau Ta criterion is selected as the outlier elimination method suitable for Beidou real-time kinematic data.The linear interpolation method,Lagrange interpolation method and cubic spline interpolation method are used to complete the short and long simulated missing data respectively.By comparing the processing results of the three methods,it is found that the linear interpolation method is suitable for interpolating the missing data in the short and long Beidou real-time kinematic data.The monitoring data completed by the linear interpolation method can not only fit the change trend of the overall data but also ensure the continuity of the data,which provides convenience for the further processing of the data.3.By analyzing the advantages and disadvantages of the Wavelet transform method and the Kalman filtering method,a two-level combination method combining the two methods is proposed.Firstly,this paper analyzes the specific impact of different denoising scales on the denoising results.By comparing the composite evaluation index T,the optimal decomposition scale of longitude data in Beidou kinematic data is 4,and the optimal decomposition scale of latitude and elevation data is 5.Then,the specific impact of the process noise covariance Q value on the denoising results in the Kalman filter method is analyzed.By comparing the composite evaluation index T,the optimal Q value of longitude and latitude data in Beidou kinematic data is 10^-27,and the optimal Q value of elevation data is 10^-16.When the surrounding environment is relatively open,the Beidou real-time Kinematic positioning accuracy after de-noising has reached the millimeter level,which is 0.4mm in the horizontal direction and 0.4mm in the vertical direction.