Resolution and Micro-Doppler Effect in Bi-ISAR System

Abstract

Compared to the monostatic radar, bistatic radar has many special characteristics because of its spatial complexity. Bistatic Inverse Synthetic Aperture Radar (Bi-ISAR) can be employed as a radar imaging tool for obtaining non-cooperative target images. In this study, we first analyze the range and azimuth resolution of a Bi-ISAR system. To analyze this azimuth resolution and its spatial-variety characteristic, a definition called con-Doppler bandwidth is introduced, which helps overcome the difficulty of the target's viewing angle diversity calculation. Then, a detailed investigation is conducted to study the micro-Doppler effect caused by the vibration and the rotation of the target in the Bi-ISAR system. By comparing the difference in the micro-Doppler effect between the Bi-ISAR system and the Mono-ISAR system, we modify the extended Hough transform to extract the real micro-motion features of the targets. Finally, we provide some simulation results to validate the theoretical derivation and to illustrate the effectiveness of the proposed method.