BISTATIC ISAR IMAGES FROM A TIME-DOMAIN CODE

Inverse-synthetic-aperture-radar (ISAR) images of radar targets are us eful for target identification, visualization, and the analysis of sca ttering centers. The major advantage of bistatic over monostatic-ISAR imaging is the reduction, in the number of computed incident angles, f rom hundreds to one. This advantage has already been demonstrated for a Physical Theory of Diffraction (PTD) code, XPATCH. The bistatic-imag ing technique can be extended to scattering data obtained from any tim e-accurate or iterative method, including low-frequency algorithms. Th is paper presents images from data obtained with a finite-volume time- domain (FVTD) code. It also provides relations between (I),the range a nd resolution of the bistatic scattering data in the Fourier domain, a nd (2) the pixel resolution and image extent in the physical domain fo r the down-range and cross-range directions. A tapering function is ap plied in the Fourier domain, to dampen ringing effects. Results are sh own for a trapezoidal plate, a cone-sphere, and a square-aperture cavi ty.