Introduction to inverse scattering problems/Scattering equations and Imaging by time reversal/Imaging by multiple signal classification and Born approximation

Speaker: Dr. Xudong Chen (NUS)

Time and Date: 10:30-11:30/13:30-15:00/15:00-16:30, Sep. 26, 2014

Place: Room 1101, East Guanghua Building, Handan Campus

Abstract

The electromagnetic inverse scattering problem of determining the locations and polarization tensors of a collection of small scatterers is investigated. The locations of scatterers are determined by the multiple signal classification (MUSIC) method and the polarization tensors are retrieved by the two-step least squares method. Multiple scattering effect is taken into account and the inverse scattering problem is nonlinear. However, the proposed method does not involve iterative evaluations of the corresponding forward scattering problem. In addition, the method provides better imaging resolution than the standard MUSIC does, and applies to degenerate scatterers to which the standard MUSIC does not apply. The underlying mathematical principle and physical insight are discussed in detail.

Biography

Dr. Xudong Chen received the B.S. and M.S. degrees in electrical engineering from Zhejiang University, China, in 1999 and 2001, respectively, and the Ph.D. degree from the Massachusetts Institute of Technology, USA, in 2005. Since then he joined the Department of Electrical and Computer Engineering, National University of Singapore, Singapore, and he is currently an Associate Professor. His research interests are mainly electromagnetic inverse problems. In particular, he is experienced in reconstructing electromagnetic parameters of obscured targets based on data of how they scatter incoming electromagnetic excitations. He has published about 110 peer-reviewed journal papers on inverse-scattering problems, material parameter retrieval, optical microscopy, and optical encryption. The total citation of his papers is about 1900 according to ISI Web of Science (SCI). He visited the University of Paris-SUD 11 in May-June 2010 as an invited visiting Associate Professor. He was the recipient of the Young Scientist Award by the Union Radio-Scientifique Internationale (URSI) in 2010. He took sabbatical leave at the Stanford University in 2012-2013, where he worked on microwave impedance tomography.