Title :
Conjugate gradient method applied to inverse scattering problem
Author :
Harada, Haruyuki ; Wall, David J N ; Takenaka, Takashi ; Tanaka, Mitsuru
Author_Institution :
Dept. of Control Eng., Kagoshima Nat. Coll. of Technol., Japan
fDate :
8/1/1995 12:00:00 AM
Abstract :
A new reconstruction algorithm for diffraction tomography is presented. The algorithm is based on the minimization of a functional which is defined as the norm of the discrepancy between the measured scattering amplitude and the calculated one for an estimated object function. By using the conjugate gradient method to minimize the functional, one can derive an iterative formula for getting the object function. Numerical results for some two-dimensional scatterers show that the algorithm is very effective in reconstructing refractive index distributions to which the first-order Born approximation can not be applied. In addition, the number of iterations is reduced by using a priori information about the outer boundary of the objects. Furthermore, the method is not so sensitive to the presence of noise in the scattered field data
Keywords :
conjugate gradient methods; electromagnetic wave diffraction; electromagnetic wave scattering; functional equations; inverse problems; minimisation; refractive index; signal reconstruction; tomography; a priori information; conjugate gradient method; diffraction tomography; first-order Born approximation; functional; inverse scattering problem; iterative formula; minimization; noise; object function; outer boundary; reconstruction algorithm; refractive index distributions; scattered field data; scattering amplitude; two-dimensional scatterers; Amplitude estimation; Diffraction; Gradient methods; Inverse problems; Iterative algorithms; Iterative methods; Minimization methods; Reconstruction algorithms; Scattering; Tomography;
Journal_Title :
Antennas and Propagation, IEEE Transactions on
