Title :
Frequency dispersion compensation in time reversal techniques for UWB electromagnetic waves
Author :
Yavuz, Mehmet E. ; Teixeira, Fernando L.
Author_Institution :
Dept. of Electr. & Comput. Eng., Ohio State Univ., Columbus, OH, USA
fDate :
4/1/2005 12:00:00 AM
Abstract :
The invariance of the wave equation under time reversal enables optimal refocusing of ultrawideband waves by time-reversal (TR) arrays. This forms the basis of recently developed TR techniques for selective (re-)focusing and inverse scattering applications. However, in electromagnetic sensing applications involving lossy or dispersive media, such as earth media, time invariance is lost and TR techniques can be significantly degraded. To alleviate this problem, a method to compensate dispersion in TR applications is proposed here. The method is based on short-time Fourier transforms and is shown to improve refocusing.
Keywords :
Fourier transforms; dispersive media; electromagnetic wave scattering; finite difference time-domain analysis; geophysical techniques; remote sensing; UWB electromagnetic waves; discrete Fourier transform; dispersive media; electromagnetic propagation; electromagnetic sensing applications; finite-difference time-domain methods; frequency dispersion compensation; inverse scattering; selective refocusing; short-time Fourier transform; time reversal techniques; time-reversal arrays; ultrawideband waves; Acoustic scattering; Dispersion; Electromagnetic scattering; Finite difference methods; Fourier transforms; Frequency; Inverse problems; Partial differential equations; Time domain analysis; Ultra wideband technology; Discrete Fourier transform (DFT); dispersive media; electromagnetic (EM) propagation in dispersive media; finite-difference time-domain (FDTD) methods; short-time Fourier transform (STFT);
Journal_Title :
Geoscience and Remote Sensing Letters, IEEE
DOI :
10.1109/LGRS.2005.846835
