Research And Simulation Of Dynamic Vector Gravimetry System

Dynamic vector gravimetry is an important tool for the geodesy and geophysics communities. With the increasing complexity of software and hardware of the dynamic vector gravimetry system, the improvement of the dynamic vector gravimetry system becomes more difficult and expensive. The simulation of dynamic vector gravity measurement is not limited by the existing hardware system, therefore the theoretical research of dynamic vector gravity measurement coud be conveniently carried out, whitch is of great significance to the actual dynamic vector gravity measurement. And the simulation of the dynamic vector gravity measurement error influenced by inertial device precision, the simulation of the solution of dynamic gravity disturbance vector, the correction of simulation results for dynamic vector gravity measurement and the design of simulation platform for dynamic vector gravity measurement have been researched in the paper and the details of the thesis are as following:(1) Based on the theory of vector gravity measurement system, the research and simulation of the effect of the error of inertial device on the precision of dynamic vector gravity measurement is carried out. The simulation model of the inertial device based on the error principle of the inertial device is established, and the output signal of the gyro is generated. The updating of the attitude matrix based on the Picard algorithm is realized. The coordinate transformation of the simulation output of the accelerometer is realized, and the solution of the gravity disturbance vector is completed. The effect of inertial devices error on the measurement precision of dynamic vector gravity is researched, by setting the error parameters of simulation model of the inertial device.(2) The gravity disturbance vector was modified using INS/GNSS data fusion method. The Calman filter for INS/GNSS data fusion is designed based on the error state theory of gravity measurement system. The observability of the inertial measurement system is enhanced, by improving the observation of INS/GNSS data fusion mode, and the error estimates with higher precision is obtained. And the vector of gravity disturbance is modified by the error estimates obtained from INS/GNSS data fusion. The correction results suggest that the improved kalman filter performed in INS/GNSS data fusion can effectively restrain the influence of inertial device's constant drift on the precision of vector gravity measurement.(3) The design of the filter is completed accoding to the time and frequency domain characteristics of the gravity disturbance vector, and the correction value of gravity disturbance vector is filtering processed. The filtering model and filtering principle of Savitzky-Golay filter, Butterworth filter and moving average filter are illustrated in this paper. And then the experiments of low pass filtering are carried out, and the experimental results shows that the Savitzky-Golay filter has certain advantages in the execution efficiency and filtering effect. The Savitzky-Golay filter is used to filter the correction value of the gravity disturbance vector, and the results suggest that the filtering process can eliminate the influence of the white noise on the gravity disturbance vector effectively.(4)The simulation platform of dynamic vector gravity measurement system with friendly interface, easy operation and full range function is designed by using the method of Visual C# and Matlab mixed programming. The carrier trajectory simulation, inertial device output simulation, GNSS data simulation, inertial navigation simulation, the solution of gravity disturbance vector simulation and filtering processing function are conveniently and quickly carried out on the Simulation platform. The simulation platform application test indicates that this platform can meet the simulation of dynamic vector gravity measurement system...