Title: Wideband imaging of extended targets with the decomposition of the time reversal operator

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

Affiliation(s): College of Mechanical Engineering, Zhejiang University of Technology; Key Laboratory of Special Purpose Equipment and Advanced Processing Technology, Ministry of Education and Zhejiang Province, Zhejiang University of Technology; National Key Laboratory of Science and Technology on Sonar, Hangzhou Applied Acoustics Research Institute

Abstract: The weighted wideband imaging approach of full signal subspaces is proposed based on the decomposition of the time reversal operator (DORT). Although each singular vector of nonzero singular values does not correspond to one of the extended targets any more, the conventional approach of selective time reversal focusing still chooses one of the signal subspaces for imaging. Simultaneously, the time-reversal MUSIC imaging is carried out at a single frequency for wideband signal. The imaging of both methods has a high background fluctuation. In order to overcome these drawbacks, the number of signal subspaces is determined by the singular values of the time reversal operator, and then DORT imaging of full signal subspaces and entire bandwidth is achieved using the generalized reflectivity coefficients as the weighted parameters. The experimental result shows that the sidelobe level of this approach is extremely decreased.