Realization Of Inverse Stokes Inversion Of Gravity Field Based On Satellite Altimetry Data

Due to the irregular characteristics of the earth's mass distribution,the quantity difference between the gravity vector at each point in the gravity field and the normal gravity vector is called gravity anomaly.Gravity anomalies are important data for studying the shape and internal structure of the earth as well as gravity exploration and correction of the orbit of the aircraft.They are widely used in the fields of physical oceanography and geophysics.However,due to the fact that the area of the ocean on the surface of the earth is much larger than that of the land,gravity measurement in deep water areas is more difficult,resulting in a serious lack of ocean gravity data.Satellite altimetry technology can solve this problem.The sea surface observation data,which can well explain the oceanic geoid and gravity anomalies,is currently the main method for obtaining ocean gravity data.The Stokes inverse algorithm is one of the main methods for inversion of the earth's gravity field using satellite altimetry data.In this thesis,MATLAB is used to program the inverse Stokes formula,and the algorithm program is verified using the EGM2008 model data.By comparing the geoid elevation data using the EGM2008 model,the inverse Stokes formula realized in this paper is used to invert the gravity anomalies in the South China Sea research area The gravity anomaly in the South China Sea research area constructed directly with the EGM2008 model found that the high and low values of the gravity anomaly and the trend and trend are completely consistent,verifying the reliability and correctness of the algorithm program.Due to the integral calculation,this method on a single thread is time-consuming.In this thesis,the GPU is used to improve and accelerate the process,which turns singlethreaded calculation into multi-threaded parallel calculation,so that the calculation time can be cut down and achieve acceleration.Collected and compiled ENVISAT satellite altimetry data,screened and preprocessed 21 consecutive cycles of ENVISAT satellite data from the 73 rd cycle to the 93 rd cycle,and established the actual satellite altimetry data to retrieve gravity anomaly data sets.Further,collinear adjustment and cross point adjustment were carried out on the actual height measurement data of screening and preprocessing to weaken the influence of time-varying information and radial orbit error.The procedure of this paper was used to invert the South China Sea area,and the gravity anomalies in the South China Sea area were obtained.The gravity anomalies in the South China Sea area constructed by EGM2008 were compared to further verify the feasibility of the algorithm.