GAMIT/Track For Real-time Monitoring Of Landslide Deformation And Water Vapor Content

With the development of science,technology and economy in China,more and more basic facilities such as dams,ports,bridges and high-rise buildings have been completed.The construction process of these facilities is very difficult and requires high safety.Deformation monitoring is often needed during construction and subsequent operation and management.Therefore,it is very important to monitor the stability and deformation of engineering structures.In addition,the continuous intensification of human production and living activities has also caused a certain degree of damage to the natural environment.In addition,rainfall,floods and the movement of geological structures have caused frequent natural disasters,which have the following characteristics: sudden occurrence,lag in obtaining monitoring data,etc.,which brings great challenges to its safety monitoring,and at the same time,it will seriously endanger people's personal and property safety.In recent years,GNSS high-precision technology and its application have been continuously improved and developed.Therefore,if the deformation information and other useful information can be obtained in time and effectively by using GNSS technology,it will provide a powerful guarantee for people's lives and property safety.This paper introduces a double-difference positioning software-Track,and explores the applicability of real-time deformation monitoring and real-time atmospheric water vapor retrieval using Track module.Focusing on the above two main research contents,this paper has carried out the following research work and reached the corresponding conclusions:1.The positioning accuracy of Track applied to deformation monitoring is analyzed.Firstly,the main application fields of Track,the way of resolving integer ambiguity and the similarities and differences of three sub-modules are introduced.Then,the positioning principle of Track,the solution flow of Track and the commands in the control file are explained in detail.Finally,the PBO Observatory with good observation quality is selected to process and analyze the data of four baselines with different lengths in different modes.The results show that Track can get good positioning results when processing short baselines under the condition of good data quality;The shorter the baseline length,the better the accuracy and stability of Track single epoch solution;When the baseline length is long,the processing effect is not good,and the vertical direction is always worse than the plane direction.2.The Track real-time deformation monitoring cloud platform is introduced as a whole,including the system hardware and software of the Track real-time monitoring cloud platform.The real-time receiving data quality of five stations built in Linxia Hui Autonomous Prefecture of Gansu Province was analyzed by using RTKLIB and TEQC software,and it was concluded that the observation quality of several stations was better.The accuracy of real-time calculation results and long-term monitoring displacement of several stations using the real-time calculation cloud platform are analyzed.The results show that the accuracy of four self-built stations in the horizontal direction is good and can reach millimeter level.In the vertical direction,for stations with short baselines,the accuracy can also reach millimeter level,but for stations with long baselines,the accuracy can also reach about 1cm.According to the monitored displacement,the displacement of the four stations in N,E and U directions is obvious.3.Real-time retrieval of atmospheric water vapor by Track is studied.The basic theory of retrieving atmospheric water vapor by ground-based GNSS is introduced,and the conversion relationship between water vapor and tropospheric moisture delay is given.Then three commonly used tropospheric delay models are briefly explained.In this paper,the solution strategy of tropospheric delay inversion in real time is introduced in detail.By comparing and analyzing the results of Track real-time retrieval with GAMIT static retrieval,it is proved that the accuracy of Track real-time retrieval of atmospheric water vapor is better.Finally,by comparing with the actual weather conditions,the change trend of Track retrieval of atmospheric water vapor is completely consistent with the weather conditions in the corresponding time period,which proves that Track real-time retrieval of atmospheric water vapor can also provide auxiliary reference for the occurrence of rainfall events.