Modeling And Simulation Of Bistatic Beverberation And Target Detection Under Beverberation

Bistatic sonar will take a significant part in field of future sonar research, as it has advantages as: larger detection range, better hiding ability, flexible range for configuration, anti-interference and mobile ability, etc, when compared with single base sonar system. Bistatic reverberation research is a crucial constituent part of bistatic sonar system. Thus, modeling and simulation of bistatic reverberation combine with statistical characteristics analysis and objective detection under reverberation are studied in this paper.In the primary part of this paper, principle of bistatic sonar is introduced which contains geometric configuration, sonar equation and detection distance of bistatic sonar system. The maximum detection range of bistatic sonar system under reverberation situation is an approximately ellipse with sending and receiving base as two focal points. Meanwhile, the detectable area is shifting towards receiving base station while with the impact of direct sound, etc. blind area will occur beside baseline. Bistatic reverberation model is constructed according to the geometric configuration of bistatic sonar system, two dimensional bistatic sound pressure and reverberation theoretical prediction formula is derived; furthermore, modeling and simulation of bistatic reverberation are fulfilled based on this formula. Based on the result above, statistical characteristics of bistatic reverberation and single base reverberation are verified to be consistent.Secondly, target demon detection techniques are used to fulfill target detection under reverberation situation. Echo signal is passed through adaptive Notch filter to filter out noise, pre- normalization which is equal to calculate the normalized weights is used to output signal. Reverberation after normalization is stationary which greatly increased the ability of target detection. This anti-reverberation technique is simple, convenient, reliable and well-oriented to achieve a stationary reverberation. Lastly, according to the result of processing pool and lake experiment data conclusion could be made that envelope detection technique is simple, convenient, effective and achieved a very good anti-reverberation. Integrated copy correlator and integrated adaptive correlator which are based on single vector sensor are introduced in this paper could be used to fulfill target echo detection under situation of noise limitation and low signal to noise ratio. Due to the fact that when receiving a echo signal the adaptive correlator could generate a real-time reference signal which could contain multi-path information and could match echo signal well, the detection ability of correlator will enhanced significantly. Thus, integrated adaptive correlator has more obvious correlation peak, a higher input SNR ratio and better performance compare to integrated copy correlator, meanwhile, adaptive correlation has better detection ability than relevant detection in multi-path channel.