Fast inverse synthetic aperture radar image simulation of complex targets using ray shooting

A series of fast algorithms for simulating the inverse synthetic aperture radar (ISAR) imagery of complex targets using the shooting and bouncing ray technique is presented. The image-domain ray spread function is first derived to directly account for the contribution of each ray in the image plane. The Sullivan (1990) scheme is next applied to achieve fast ray summation. Using the fast algorithms, the ISAR image simulation time can be reduced to about one hour on a Silicon Graphics Indigo workstation for a realistic airplane at X-band. This is more than two orders of magnitude less than that of the standard frequency-aspect image formation process. The simulation methodology and the simulated imagery of a helicopter with rotating blades are also presented