Journal of Systems Engineering and Electronics ›› 2021, Vol. 32 ›› Issue (6): 1381-1393.doi: 10.23919/JSEE.2021.000118

• ELECTRONICS TECHNOLOGY • Previous Articles     Next Articles

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

Wenshu DAI1,*(), Enming ZHENG2(), Kaikai BAO3()   

  1. 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
  • Received:2020-03-06 Accepted:2021-11-09 Online:2022-01-05 Published:2022-01-05
  • Contact: Wenshu DAI;;
  • About author:|DAI Wenshu was born in 1987. She received her B.S. degree in ocean technology from Ocean University of China in Qingdao in 2010 and Ph.D. degree in 2015 from the Institute of Acoustics, Chinese Academy of Sciences, Beijing. Now she is a lecturer in North University of China and does research in the Key Laboratory of Instrumentation Science & Dynamic Measurement. She is dedicated to the research of underwater signal processing and detection, array engineering technology, underwater acoustic communication, and water acoustics physics. E-mail:||ZHENG Enming was born in 1985. He received his B.S. degree from Harbin Engineering University in 2009 and was recommended to the Institute of Acoustics, Chinese Academy of Sciences (IACAS), Beijing, China. He received his Ph.D. degree in 2014 from IACAS as a first class graduate. Now he is working in the Weak Signal Detection and Processing Laboratory, Institute of Acoustics, Chinese Academy of Sciences, and he is an assistant researcher. His research interests include signal processing and detection, signal processing technology of sound pressure and velocity, array engineering technology, and array signal processing techniques of underwater acoustic communications and positions. E-mail:||BAO Kaikai was born in 1989. He received his B.S. degree in electronic science and technology from Southwest Jiaotong University, Chengdu, China, in 2011 and M.S. degree in microelectronics and solid-state electronics from University of Chinese Academy of Sciences, Beijing, China, in 2014. His research interests include the development of micro-electro-mechanical systems and underwater wireless sensor networks. E-mail:
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (51875535) and the Natural Science Foundation for Young Scientists of Shanxi Province (201701D221017;201901D211242)


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 in 2-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.

Key words: towed linear array sonar, target radiated noise spectrum, line spectra level ratio (LSR), receiver operating characteristic (ROC) curve, post-processing