Vehicle-Borne Gravity Vector Measurement Method Based on SINS/GNSS/LDV Integrated Navigation

At present, vehicle-borne gravity measurement mainly focuses on the gravity scalar, and vector measurement has not been developed because of the limitations in attitude measurement accuracy, velocity measurement accuracy and acceleration measurement accuracy. In this study, to address the problems encountered in traditional gravimetry, integrated with the high-precision Strapdown Inertial Navigation System (SINS) and Laser Doppler Velocimeter (LDV) developed by our group, a vehicle-borne gravity vector measurement method based on SINS/GNSS/LDV integrated navigation system is proposed. By analyzing the error model, the device accuracy requirements were obtained, and the system was built for the experiments. Without post-error compensation, the internal coincidence accuracy of vehicle-borne gravity vector measurement is within 3.3 mGal/1.7 km. Compared with the traditional gravity measurement method based on SINS/GNSS, the internal coincidence accuracy of the vertical, east and north gravity vector is improved by 17%, 34% and 38% respectively. The use of a new integrated system to obtain the key factors affecting the vector gravimetry can directly improve the accuracy of the disturbance measurement, thus providing a basis for obtaining higher-precision and higher-resolution deviation of vertical (DOV) to determine geoid and gravity compensated navigation.