Beam-tracing-based inverse scattering for general aperture antennas

Iterative techniques are presented for two-dimensional inverse scattering f rom electrically large regions. The region is illuminated by transmitters w ith arbitrary profiles; this is an escalation in complexity from the line-s ource and the plane-wave excitations considered in many previous inverse-sc attering studies. Imaging algorithms require an accurate and efficient forw ard model. Here a Gaussian-beam algorithm is utilized as a forward solver a nd is incorporated into an iterative-Born inversion scheme. General antenna profiles are incorporated into the algorithm by use of the matched-pursuit s technique, by which the aperture fields are matched to the beam-tracing a lgorithm. Results are presented for several cases in which the simple Born approximation fails. Issues addressed include the types of profiles that ca n be successfully imaged, suitable antenna distributions, and the range of parameters over which the scheme is effective. Performance of the algorithm in the presence of noisy data is also tested. (C) 1999 Optical Society of America [S0740-3232(99)02209-7] OCIS codes: 290.0290, 280.0280, 050.0050.