Target Sound Field In The Air Modeling And Software Implementation

When develop passive acoustic localization system directed mainly at targets flying low and maneuver targets on the ground, in order to gain data received by array elements under different motion states and acoustic field to demonstrate system reliability and accuracy, it needs large number of out-field experiments. Obviously, it will take up considerable of human and non-human sources. Moreover, the data received by array can hardly satisfy every requirement for varying environment parameters. The paper simulates the system of array receiving helicopter radiate noise is achieved by designing a system including hard ware and soft ware. By setting several parameters, the simulation system simulates the specific frequency helicopter radiate noise and data received by array elements according to specific environment and given flight route. After creating simulation data, it can analyze data in frequency field and estimate time-delay between every two elements data to gain orientation angles of target. The environment parameters of the simulation system include every aspect, therefore it can approximate real environment as far as possible. The system developed with Visual C++ language including powerful functions, provides a user- friendly interface and several parameters that can be changed at will, to facilitate simulating all kind of acoustic field environment. The data simulated by the simulation system can replace outfield experimentation data mostly, so it can economize large numbers of manpower and material resources, assess several system performances in theory design phase, and shorten research period.The main works are as follows:1. Study the acoustic field character of helicopter and armored car. Combining with measured data, analyze time-field and frequency-field characters of this two kinds acoustic signal. Study on several factors influent the targets acoustic signal's transmission such as: air temperature, air humidity, wind velocity, wind direction, rain and snow. Build target acoustic signal's transmission and attenuation math model.2. Study character of the array elements receiving target signal. Build locality error model, element scope and phase response model, moreover, receive target signal with these models. Then combining the factors that influent generalized cross correlation algorithm estimating the time delay between two element received data, a method basing on high sample, which is used to create element received high accuracy time delay between two elements data, is brought forward.3. Discuss object-oriented programming language's merits, combining software...