IMAGE DOMAIN RAY TUBE INTEGRATION FORMULA FOR THE SHOOTING AND BOUNCING RAY TECHNIQUE

A simple image domain ray tube integration formula is presented to eff iciently compute the inverse synthetic aperture radar (ISAR) image of a complex target by the shooting and bouncing ray (SBR) technique. Con trary to the conventional approach where the ISAR image is obtained by inverse Fourier transforming the computed scattered field data over f requency and aspect, this image domain formula gives the contribution of each ray to the overall ISAR image directly. Under the small angle approximation and utilizing the bistatic-monostatic equivalence, the i mage domain ray tube integration formula is determined in closed form. Simulation results using the SBR-based code ''Xpatch'' show that the direct image domain method results in good image quality and superior time performance when compared to the conventional frequency aspect ap proach.