Research Of Key Technologies In The Underwater Target Passive Location System

Because of its wide applications in military and civil, the underwater target passive locating technology becomes the focus of the research in the field of underwater location. Because of the theoretical research and technology of underwater locating technology has been continuously expanded at home and abroad, at present the study has been involved in underwater acoustic engineering, signal processing, signal detection, algorithm implementation, software design and other related fields. In view of the complex underwater channel, this paper takes a project as background, does researches on the key technologies of underwater passive location system.This paper firstly introduces background significance, applications and research situation of the passive localization of underwater technology, then analyzes several characteristics of underwater acoustic channel, as well as two basic principles of underwater passive location system. At last, we select the positioning principle based on the time difference as the system positioning principle through analysis and comparison of the two kinds of basic principles which is introduced in this paper. The paper brings the three key components of this system after determining the localization principle, then through the comprehensive analysis on the common source of positioning system error and positioning system performance evaluation indicators, finally selects the root mean square error (RMSE) and positioning accuracy factor (GDOP) two parameters defined as accuracy evaluation index of passive positioning system under the water. On this basis, through the analysis and comparison of several algorithms that based on time difference positioning estimation and delay estimation, it selects the generalized correlation time delay algorithm and cooperative localization algorithm based on the combination of the Chan algorithm and the Taylor series expansion method, which implement in Matlab environment.In order to verify the validity and accuracy of the algorithm, we build the passive positioning system in water pool environment, which uses acoustic sensor array to acquire target acoustic signal passively. The positioning experiments are completed by three key steps, including the pre-processing of the acoustic signal, time delay estimation, as well as positioning estimation. The experiments show that the co-location algorithm is with high positioning accuracy in the experimental environment, which is able to meet the requirements of the actual system. Ultimately, by analysis and comparison of the respective characteristics of mixed programming of VC++and MATLAB, this paper selects mixed programming methods based on the dynamic link library (DLL), and then introduces three main positioning modules in detail. Finally, uses mixed programming methods dynamic that based on link library (DLL), completes the underwater target positioning system applications program which designed based on co-localization algorithm.