Study On Acoustic Detection Of Targets About Three-dimensional Burst Point

In recent year, the location of the burst point of ground proximity is a popular topic. In a weapon system, the explosive location of a projectile is one of the most important indexes to evaluate the performance of the weapon. Due to the complex environment of the testing ground and the space bombing of the projectile point diversity, the spatial location of the burst point is difficult to obtain accurate. The more advanced method is to adopt the large field of video theodolite to measure the burst point. However, the system is large, expensive, making it impossible to be promoted. It is necessary to study a kind of economic and practical detection system.With the increasingly widespread applications of a variety of positioning systems, passive acoustic detection system has also been more and more attention. This paper putted forward network of five-element cross array algorithm, because of location system for passive acoustic array algorithms in four-element cross positioning accuracy affected by the target azimuth. The positioning principle and the geometric relationship among the elements had been studied. The effect of the array element spacing, the azimuth angle, pitching angle and other factors on positioning precision had been researched and simulated.Firstly, the propagation characteristic of the low-level sound of acoustic wave was analyzed. Several factors, affecting the speed of sound propagation in the near surface layer, were studied. And then gave a brief introduction to the characteristics of the blast wave. Time-delay estimation algorithm and geometrical array were both of pivotal technologies of acoustic orientation were studied. By the compare of different methods of time-delay estimation, the method of inter-related delay estimation was chose in the paper. In the problem of the geometric array of the positioning system, this paper gave a detailed discourse for the four-element cross array and network of five-element cross array algorithm and made an error simulation of the positioning error of the two arrays. The result of the simulation showed that the network of five-element cross array algorithm was better than the four-element cross array. According to the positioning requirements of the network of five-element cross array algorithm, a hardware system had been built by microcontroller of AT89S52.The positioning system was divided into three functional modules:the acoustic signal acquisition module, Microcontroller timing module and the wireless communication module to elaborate. Finally, the acoustic positioning system was tested indoor and outdoor.Simulation results and experimental results showed that the accuracies of burst point of the distance and direction-finding have been enhanced. And the positioning accuracy of the burst point by target azimuth influenced was improved.