Terrain aided navigation can yield accurate navigation results for the long-endurance operation of autonomous underwater vehicles(AUVs). Point-mass filtering(PMF)theory is an important method to yield accurate terrain aided navigation results for AUVs，but the search for the spatial relationship calculation between the irregularly distributed bathymetric measurements and the gridded prior topographic map in mass point weight calculation will lead to a substantial amount of computational cost and severely weaken the real-time performance of the terrain matching navigation algorithm. An efficient PMF method for seabed terrain aided navigation is proposed in this paper. The proposed method yields efficient and accurate grid interpolation results for bathymetric measurements by constructing an Sparse Pseudo-input Gaussian Processes(SPGPs)model and builds a gridded probabilistic map using the beliefs of these interpolation results. The framework of a PMF is constructed，and a mass point weight calculation method using a probabilistic map is proposed to improve the positioning accuracy of the terrain aided navigation system by considering the difference in the interpolation confidence of nodes in the grid map. An at-sea data collection experiment was conducted in Zhongsha Reef，Qingdao，and play-back experiments were conducted by loading these field data. The experimental results showed that the proposed method can provide accurate interpolation results efficiently，and the proposed terrain aided navigation method can yield accuratenavigation results for AUVs with a real-time location error less than 3m(CEP).
