Technology of gravity aided inertial navigation system and its trial in South China Sea

Abstract

The technology of gravity aided inertial navigation system and its trial in South China Sea is presented in this study. The principle and technology are introduced and the results of its sea trial in South China Sea are illustrated and discussed. The gravity data was measured with marine gravimeter. After data preprocessing, multi-model Kalman filter iterative algorithm is used to estimate position of the underwater vehicle in the stored gravity reference maps. At last the navigation results were compared with GPS's record, a 1.92 n miles optimal position accuracy of two actual marine trajectories is obtained. Furthermore, two aspects (the accuracy of measurements and gravity reference map, the gravity feature variations) and three key parameters, which influence the position accuracy, are discussed and analysed. The trial results show that the gravity aided inertial navigation system is feasible and effective, and the position accuracy of inertial navigation system can be obviously improved with this proposed navigation approach.