Sensors 2018, 18(4), 1154; doi:10.3390/s18041154
Coherent and Noncoherent Joint Processing of Sonar for Detection of Small Targets in Shallow Water
1
College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China
2
Hangzhou Xuejun High School, Hangzhou 310012, China
*
Author to whom correspondence should be addressed.
Received: 25 February 2018 / Revised: 29 March 2018 / Accepted: 3 April 2018 / Published: 10 April 2018
(This article belongs to the Special Issue Ultrasonic Sensors 2018)
Abstract
A coherent-noncoherent joint processing framework is proposed for active sonar to combine diversity gain and beamforming gain for detection of a small target in shallow water environments. Sonar utilizes widely-spaced arrays to sense environments and illuminate a target of interest from multiple angles. Meanwhile, it exploits spatial diversity for time-reversal focusing to suppress reverberation, mainly strong bottom reverberation. For enhancement of robustness of time-reversal focusing, an adaptive iterative strategy is utilized in the processing framework. A probing signal is firstly transmitted and echoes of a likely target are utilized as steering vectors for the second transmission. With spatial diversity, target bearing and range are estimated using a broadband signal model. Numerical simulations show that the novel sonar outperforms the traditional phased-array sonar due to benefits of spatial diversity. The effectiveness of the proposed framework has been validated by localization of a small target in at-lake experiments. View Full-TextKeywords:
spatial diversity; coherent processing; detection; sonar; at-lake experiment
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Pan, X.; Jiang, J.; Li, S.; Ding, Z.; Pan, C.; Gong, X. Coherent and Noncoherent Joint Processing of Sonar for Detection of Small Targets in Shallow Water. Sensors 2018, 18, 1154.
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