Research Article Active Sonar Detection in Reverberation via Signal Subspace Extraction Algorithm | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2010 Article ID 981045 10 pages doi 2010 981045 Research Article Active Sonar Detection in Reverberation via Signal Subspace Extraction Algorithm Wei Li 1 QinYu Zhang 1 Xiaochuan Ma 2 and Chaohuan Hou2 1 Communication Engineering Research Center Shenzhen Graduate School Harbin Institute of Technology Shenzhen Guangdong 518055 China 2 Institute of Acoustics Chinese Academy of Sciences Beijing 100190 China Correspondence should be addressed to Wei Li liwei@ Received 29 November 2009 Revised 26 March 2010 Accepted 3 June 2010 Academic Editor Zheng Zhou Copyright 2010 Wei Li et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. This paper presents a new algorithm called Signal Subspace Extraction SSE for detecting and estimating target echoes in reverberation. The new algorithm can be taken as an extension of the Principal Component Inverse PCI and maintains the benefit of PCI algorithm and moreover shows better performance due to a more reasonable reverberation model. In the SSE approach a best low-rank estimate of a target echo is extracted by decomposing the returns into short duration subintervals and by invoking the Eckart-Young theorem twice. It was assumed that CW is less efficiency in lower Doppler than broadband waveforms in spectrum methods however the subspace methods show good performance in detection whatever the respective Doppler is. Hence the signal emitted by active sonar is CW in the new algorithm which performs well in detection and estimation even when low Doppler is low. Further a block forward matrix is proposed to extend the algorithm to the sensor array problem. The comparison among the block forward matrix the conventional matrix and the three-mode array is discussed.