Research And Application Of Target Motion Analysis Algorithm Based On Underwater Warfare System

With the rapid development of modern science and technology, positioning technology has been widely used in the field of aviation, marine, transportation and other civil and military fields. Under modern warfare environment, it was very important to detect the location of the enemy target, because it helped to understand the military deployment of the target, and could destroy them before the threat comes. The estimationg of underwater target was an important part of related researches. It was difficult because of the complex underwater environment and serious attenuation of electromagnetic wave in the water. In the current research, when passive sonar received target radiated noise, it could extract the bearing and the Doppler frequency. Therefore, it was significative and valuable to study the positioning technology of underwater target based on the bearing and Doppler frequency.In this paper, based on the bearing and Doppler frequency, two improved target motion analysis algorithms were put forward, the main research contents as follows:Firstly, the Doppler frequency space optimize search algorithm of target motion analysis was researched. Because of the anomalous datas in the observation, the error of the result was reduced by pretreating the azimuth sequence. In this paper, the filter equation was transformed from the nonlinear to the linear one. When the Doppler frequency was matched, a combined global search and local search optimize search matching algorithm was introduced, that the best estimate problem of the search element’s objective function was transformed into a multi-peak and nonlinear optimization problem. The algorithm determined key areas by global search, and improved the accuracy of the search element, which made the objective function to be the best by local search in key areas. Experiments showed that the algorithm enhanced the precision of target parameter.Then, the adaptive Kalman filtering algorithm of target motion based on the Doppler frequency was studied. The Kalman filtering equation based on the bearing and Doppler frequency was designed, according to the target state equation and measurement equation. Working in a passive mode, the result of instability, slow convergence and low convergence precision were easy to appear when the underwater target was located by using Kalman filtering algorithm. In the algorithm, the statistical characteristics of the system process noise and measurement noise in real-time was estimated, and the error caused by linearizing observation model was dynamically compensated. Experiments showed that the adverse impact caused by the observation error was reduced and the accuracy of the parameters was improved in the algorithm.Finally, the two target motion analysis algorithms were applied to underwater combat system. The submarine combat system was designed, which mainly included the target detection and tracking, data processing, threat assessment and target motion parameter analysis and implementation of enemy torpedo attacking, and other functions.The simulation results showed that the algorithms improved the torpedo’s hit rate.