Research On Underwater Positioning Method Based On Terrain Matching

With the rapid development of underwater autonomous vehicle,navigation positioning of the vehicle has become a more important issue.There are a variety of navigation and positioning methods around the world.Because the electromagnetic wave can not be transmitted over long distances underwater,the positioning navigation of underwater vehicle mainly adopts the inertial navigation system.Although the inertial navigation system can output a variety of navigation parameters and has a certain accuracy,the inertial navigation system has the problem of accumulation of errors,so the navigation technology of underwater vehicles generally use inertial navigation system as the main integrated navigation system,in which terrain matching auxiliary navigation technology as a passive navigation has been rapidly developed.In this paper,the navigation and positioning of underwater vehicles is mainly based on the principle of terrain matching assistant navigation algorithm.By studying the principle of terrain auxiliary navigation and simulating the algorithm,the validity of the terrain matching algorithm in navigation and positioning of auxiliary inertial navigation system is verified.This paper mainly studies the composition of terrain matching assistant navigation system,and studies the inertial navigation system,digital map,and the classical terrain matching algorithm terrain contour matching(TERCOM)and the Sandia inertial terrain assisted navigation(SITAN)algorithm for inertial navigation system respectively.The digital topographic map is simulated by discrete two-dimensional stochastic process,which provides the basis for the subsequent simulation.The simulation of the inertial navigation system is carried out to verify the accumulation of the error,and the terrain-assisted navigation algorithm is proposed.The matching algorithm is the core of the terrain matching,and the terrain matching algorithm is understood by studying the TERCOM and SITAN algorithms.For the SITAN algorithm,there are terrain linearization errors,and the application of Monte Carlo based particle filter algorithm in terrain matching is proposed.Because the traditional TERCOM and SITAN use the one-dimensional terrain elevation sequence,a two-dimensional terrain matching algorithm based on Hu moments is proposed,which verifies the effectiveness of the method and the better anti-noise performance.