Narrow band time-frequency space matched passive detector for underwater signal

摘要

Passive target detection under low signal-to-noise ratio is essential in various underwater circumstances, but difficult as lacking of targets' prior information, special propagation characteristics and effect of background noise. Based on the time-frequency representation, we develop a narrow band time-frequency space matched method. The time-frequency matrix is derived based on the ray theory, the warping expression, and the pooling function. Then the sliding cumulative convolution of the matrix obtains a higher signal to noise ratio output. The likelihood ratio test detector is derived for passive target detection. Analysis and the ocean experiment results show that the proposed approach outperforms other passive detectors. (C) 2021 Elsevier Ltd. All rights reserved.