Target rotation motion estimation from distributed ISAR data

The use of multiple radar systems, carried by a set of air platforms flying in formation, has been demonstrated to be able to provide ISAR images of rotating targets with increased cross-range resolution, up to the number of considered platforms or even higher. To correctly focus the multi-sensor ISAR image with improved resolution the knowledge of the target motion characteristics is required. To accomplish this task different model-based and model-free estimation techniques of the target rotation motion from multi-sensor ISAR data are proposed in this paper. The Cramer Rao Bound and a complete simulated performance analysis are provided showing the improvement in the estimation accuracy arising from the use of multi-sensor data with respect to conventional (single sensor) techniques. Moreover, the proposed techniques are validated by applying them to live distributed ISAR data acquired in anechoic chamber.