Technology Study On Seabed Terrain Matching Navigation

To be able to make full use of known information is one of the significant reasons why, nowadays, all kinds of military equipments become intellectualized and automotive. As one of the usual combined navigation systems, the terrain-aided inertia navigation system does well in this and gains great performance benefit. Terrain matching is one hot point in this paper, whose most outstanding problems is how to match with velocity and veracity.When studying the velocity part, the author introduces the SSDA at first, which is very superior to FFT in velocity; then, the RLS algorithm is used to process the contour line to determine the match-up point, angle error and the zoom proportion. The search strategy eliminates the areas which can't include the match-up point in one side; in the other side, it makes a difference between areas including the match-up point with different likelihood. With this search strategy, the most likely several or one usually include the match-up point. So this strategy will increase the velocity and not lose any potential match-up point.When discussing the veracity part, because the ambiguity of the match-up point is induced by the correlation of the terrain, this paper introduces the time sequence model, estimates its coefficients and counter-correlates the terrain section at last. This mechanism will not only be a practical apply of the theory of signal processing, but also provide means to design the enhancing operator which is used to be designed by experience.At last, this paper give two scheme designs of the terrain-aided inertia navigation system, including SITAN and TERCOM. The SITAN system is aim at the track mode of the navigation, three data sources are used to estimate the position error of the submarine, including the depth directly below, the terrain database, and the outputs of the inertia system. The TERCOM system is aim at the search mode of the navigation, which synthesizes algorithms discussed before, using the match-up point as the estimation of the position of the submarine directly. SITAN and TERCOM are not separated absolutely; interactions between these two systems are also mentioned in this paper.