ISAR imaging for rapidly spinning targets

A new method of ISAR imaging is proposed in this paper for rapidly spinning targets in space. This type of target rotates several rounds around a stable axis during the imaging processing time. The spin motion induces multi period sinusoidal modulation in both range and Doppler domain of the radar echoes, which cause the conventional Range-Doppler (R-D) algorithm to become invalid in ISAR imaging. The presented method analyses the echo model of the target spinning around an arbitrary axis. Then it resamples the echo sequence under the condition of estimation of the target spinning period, and reconstructs the image from this new echo sequence. The simulation result shows that this method can avoid the influence of the target´s uniform speed spin motion and achieve ISAR image effectively.