Research On The Detection Technology Of Multi-static Based On Linear Array

With the increasing severity of marine issues,the world began to focus on the development and utilization of marine resources,research and development of underwater military technology aggressively.Multi-static sonar can work with good invisibility,independently of the target state,so it has a unique advantage in the underwater target detection and positioning,and has been widely used in the civilian and military fields.Under the background and significance,the detection technology of multi-static was studied based on the linear array in the thesis.Firstly,the detection scheme of multi-static system was verified.The parameters of multi-static system were designed according to the sonar equation and azimuth estimation.The detection range of monostatic,bistatic and multi-static were achieved by calculating the received SNR.The influence of different geometrical configuration and baseline length on detection range with one transmitter and two receivers multi-sonar were researched.The spatial distribution of the detection range of multiple sonar was given under the condition of triangle configuration.From the working principle and system configuration of bistatic sonar and multi-sonar,the algorithm of target location and the spatial distribution of positioning accuracy were achieved.What's more,the regularities of distribution were also analyzed.Secondly,the ability of array signal processing was analyzed based on uniform line array.The principles and specific calculation method of time gain and space gain were studied.The experimental data of South China Sea was used to validate the results and was compared with the theoretical value Also the causes of errors were analyzed.Finally,the detection range and positioning accuracy of the system were evaluated by analyzing of the parameter estimation performance of linear array.The delay of echo signal was simulated by using the method of correlation to obtain the curve of time delay estimation precision in the different SNR.Also,a solution to the problem of fuzzy of linear array direction was proposed by using the location of the sound and DOA estimation,and the direction of horizontal array used in Songhua Lake was calibrated.The noise characteristics in the received signal were analyzed and the target bearing estimation accuracy under different SNR were computed.