A Novel Cross-Line Adaptive Domain Matching Algorithm for Underwater Gravity Aided Navigation

The matching low-efficiency and mismatching of the domain-based sequence matching are two main problems affecting underwater navigation ability. Compared with in-domain mismatching, out-of-domain mismatching occurs outside the matching domain and its positioning error is larger, which results in more serious navigation effects. To address these problems, a cross-line adaptive domain matching (CADM) algorithm is proposed to improve the positioning efficiency and out-of-domain matching capacity of underwater navigation. Different from the canonical sequence correlation matching algorithm, the proposed method realizes the domain-center adaptive screening by using a cross-line pre-matching trick and obtains a better repositioning for the vehicle's real position by employing an adaptive domain re-matching mechanism. Simulation results show that the proposed method can effectively improve the positioning efficiency and out-of-domain matching performance of underwater gravity-matching navigation. In two track tests, the matching efficiency is averagely improved by 82%, the number of the out-of-domain mismatches is reduced by 94.87% and 97.22%, and the improvement ratios of the out-of-domain matching accuracy indexes are almost over 86%, which adequately verify the outstanding matching capacity of the proposed method. And it can provide a new choice for underwater autonomous passive navigation in the future.