Title: Time reversal imaging of suspended target in strong reverberation

Author(s): LI Chunxiao; GUO Mingfei; WANG Zhongkang;

Affiliation(s): 1. MOE/Zhejiang Provincial Key Laboratory of Special Purpose Equipment and Advance Manufacturing Technology, College of Mechanical Engineering, Zhejiang University of Technology; National Key Laboratory of Science and Technology on Sonar, Hangzhou Applied Acoustics Research Institute

Abstract: The weighted wideband time-reversal imaging approach of full signal subspaces was proposed. The extended target is modeled as an infinite number of independent point-like scatterers, and the imaging is constructed by accumulating all time-reversal images over all signal subspaces and the entire bandwidth in the region of suspected targets. On the bottom of a laboratory water waveguide, a cylindrical shell was used to produce reverberation. Two experiments were carried out. The first experiment is that an extended target was suspended near the cylindrical shell, whose echo and the reverberation reflected by the cylindrical shell were in different time windows. The second experiment is that a point-like target was suspended above the cylindrical shell, thus the echo and the reverberation were in the same time window. The experimental results show that the imaging quality of the proposed method is better than that of the conventional time reversal imaging methods for weak suspended targets in a strong reverberation background.