Research And Application Of High Precision Satellite Settlement Monitoring System Based On GAMIT/GLOBK

In the south of China,the terrain of mountains and hills is complex,and some mountains have been completely mined out under the ground.In these mined out areas,there are usually many large buildings and facilities,such as railways,substations and water storage stations.These buildings are very unsafe,if the cost of regular inspection by hand will be very large,the cycle will be very long,so it needs a scientific and effective method for monitoring and early warning.At present,GNSS and ground reference station system are usually used to obtain the coordinate data of monitoring points through satellite receiver,which can be used as the basis of whether settlement occurs.In this paper,the PPP single point positioning principle,RTK dynamic differential positioning principle and the basic methods of baseline solution and post-processing are described,and the error sources and how to eliminate or weaken these errors are analyzed.After that,we focus on the GAMIT / GLOBK high-precision solution algorithm.Finally,we can get the fixed solution of the combination of time domain and space domain,and its precision can reach millimeter level.Finally,a high-precision settlement early-warning and monitoring system is built based on GAMIT / GLOBK algorithm,which can be used to remotely monitor the settlement coordinate data changes of large-scale substation equipment in remote mountainous areas.The system is mainly composed of four sub-systems: field monitoring,local solution server,cloud data forwarding server and client.The on-site monitoring terminal is responsible for the collection of GNSS original coordinate data;the local solution server is responsible for the baseline solution and local storage of coordinate data;the cloud data forwarding server is responsible for the forwarding of accurate coordinate data;the client is responsible for the analysis and display of final data.The settlement monitoring system built in this paper has the following characteristics: 1)high degree of system integration;2)high accuracy of data solution(up to millimeter level);3)real-time transmission of coordinate solution data;4)distributed storage of solution coordinate data.