| An electromagnetic inverse scattering problem for plane wave incidence on a perfectly conducting closed convex scatterer under the physical optics solution is considered. Under these assumptions, the Kennaugh-Cosgriff formula is extended to the bistatic case and the ramp response is applied to radar imaging via the classical Radon problem of reconstruction from cross-sectional areas. Excellent images are reconstructed for the test sphere, using data obtained from the Mie series. To account for the polarization characteristics of vector electromagnetic inverse scattering in both the monostatic and bistatic cases, Bennett's polarization correction to physical optics is applied and extended to obtain an asymptotic relationship between the phase difference of the co-polarized elements of the bistatic scattering matrix and the principal curvature difference at the specular point. The relationship is verified with monostatic scattering measurement data for the ellipsoid. To extract any information of specular geometry, it is suggested that the specularly reflected return be separated from the creeping waves in the scattered field by a separation technique, which reveals the relative strength of creeping waves and specular returns on signal-processing of the measurement data collected for the perfectly conducting ellipsoid. Based on physical optics, a quick estimation of the bistatic cross-section for the perfectly conducting sphere is obtained. |
