Algorithm Research And System Design Of Underwater Acoustic Detection Based On A Single-transmission And Multi-reception Array

The 21 st century is a century of oceans.The ocean is of strategic importance to the survival and development,sovereignty and security of a country.In order to adapt to China's economic and social development,the state has even put forward the strategy of "maritime power".The difficulty in rationally exploring and using marine resources lies in the detection of the underwater environment.Spatial spectrum estimation is a key technology for underwater detection,which has been paid more and more attention in industry and academia.In recent years,DOA estimation algorithm based on signal sparse representation has been developed rapidly.It has good estimation results under low SNR,few snapshots and coherent sources.However,for distributed sources,since the spatial sparsity assumption cannot be satisfied well,the spatial spectrum estimation method based on the sparse reconstruction criterion has no good performance.In addition,traditional spatial spectrum estimation methods are mostly based on passive detection model.Based on the above background,the main work of this paper is as follows:Firstly,based on the characteristics of active detection in the single-transmission and multi-reception array system,this paper proposes a time delay estimation method based on sparse constraint and further extends to joint angle distance estimation.Different from the traditional angle-distance estimation method based on passive detection model,the proposed method utilizes the waveform characteristics and synchronization information of the transmitted and received signals,and further utilizes the sparse features.The simulation shows that the proposed method can achieve higher-precision spatial spectrum estimation than the passive detection parameter estimation method.In addition,by analyzing the inadequacy of sparse signal representation in the distributed source model,a two-dimensional angle-distance joint estimation mathematical model based on low rank constraint criterion is established,and the low rank characteristic of joint distribution is analyzed.Based on this,this paper proposes an angle distance joint distribution estimation algorithm based on low rank matrix reconstruction.The simulation shows that the method based on low rank constraint criterion has better estimation performance than sparse constraint method for two-dimensional spectrum estimation of distributed sources.Finally,this paper designs and implements a single-transmission and multi-receptionsonar underwater detection system,focusing on the design of the structure of sending and receiving data and the working logic of the system.it can display the underwater detection results in real time,and supports saving the data received by the sonar,which is convenient for subsequent algorithm research on the computer simulation platform using real data.Moreover,based on the system,the test and verification of the algorithm proposed in this paper are completed.