A semi-physical simulation method for underwater gravity measurement based on velocity observation

With the improvement of the measurement accuracy of inertial navigation system, the technology research of gravity matching assisted navigation has gradually been applied. Considering that the difficulty of gravity assisted navigation itself lies in the acquisition of prior maps and the measurement of gravity anomaly, and the cost and cycle of the early underwater test are too high, it is not suitable for a large amount of data collection and algorithm improvement and optimization. Therefore, this paper proposes a semi-physical simulation method of underwater gravity measurement based on velocity observation, to verify the feasibility of combined gravity anomaly measurement of new sensor and inertial survey with real ocean data and simulation and external information. In this paper, the trajectory generator based on the measured trajectory, with the laser Doppler meter (LDV) and depth meter replace acoustic Doppler meter (DVL) and GPS height information, finally use the actual sea data for simulation and data analysis, and verify the influence of velocity change and height error on the results. When the velocity error within 0.1m / s and height error within 1m, after the leveling treatment of gravity abnormal discrepancy value changes within 0.1 mGal, so that through the trajectory simulation and add velocity, height error can approximate simulation velocity and depth meter gravity device measurement results, and verify the feasibility of the algorithm.