Distributed ISAR focusing for targets undergoing 3D motion

The issue of focusing ISAR images with improved cross-range resolution of targets undergoing 3D motion observed by multiple radar systems is here addressed. Both multi-aspect and multi-grazing acquisition geometries are here considered. The Distributed Point Spread Function is devised with two possible approaches: (i) ID Multi-Aspect/Multi-Grazing and (ii) 3D approach, when the distributed processing is matched to the vertical/horizontal or to the effective component of the rotation motion respectively. The needed focusing technique is presented with the results obtained against simulated data; performance analysis shows that, despite some spatially variant degradation experienced with respect to ideal case (i.e. acquisition geometry completely matched to the motion characteristics) ISAR images of quality considerably higher than in the conventional single sensor case can be obtained.