A method of line spectrum extraction based on target radiated spectrum feature and its post-processing  

作　　者：DAI Wenshu ZHENG Enming BAO Kaikai 

机构地区：[1]Key Laboratory of Instrumentation Science&Dynamic Measurement,North University of China,Taiyuan 030006,China [2]Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China [3]Northern Institute of Automatic Control Technology,Taiyuan 030051,China

出　　处：《Journal of Systems Engineering and Electronics》2021年第6期1381-1393,共13页系统工程与电子技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(51875535);the Natural Science Foundation for Young Scientists of Shanxi Province(201701D221017,201901D211242)。

摘　　要：To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum that the high intense and stable line spectrum is superimposed on the wide continuous spectrum.This method modifies the traditional beam forming algorithm by calculating and fusing the beam forming results at multi-frequency band and multi-azimuth interval,showing an excellent way to extract the line spectrum when the interference and the target are not in the same azimuth interval simultaneously.Statistical efficiency of the estimated azimuth variance and corresponding power of the line spectrum band depends on the line spectra ratio(LSR)of the line spectrum.The change laws of the output signal to noise ratio(SNR)with the LSR,the input SNR,the integration time and the filtering bandwidth of different algorithms bring the selection principle of the critical LSR.As the basis,the detection gain of wideband energy integration and the narrowband line spectrum algorithm are theoretically analyzed.The simulation detection gain demonstrates a good match with the theoretical model.The application conditions of all methods are verified by the receiver operating characteristic(ROC)curve and experimental data from Qiandao Lake.In fact,combining the two methods for target detection reduces the missed detection rate.The proposed post-processing method in2-dimension with the Kalman filter in the time dimension and the background equalization algorithm in the azimuth dimension makes use of the strong correlation between adjacent frames,could further remove background fluctuation and improve the display effect.

关 键 词：towed linear array sonar target radiated noise spectrum line spectra level ratio(LSR) receiver operating characteristic(ROC)curve POST-PROCESSING 

分 类 号：TB56[交通运输工程—水声工程]