Polar reformatting for ISAR imaging

Polar reformatting is a technique that has been developed and used extensively in spotlight SAR processing. The prerequisite for using this technique is to know the radar's aspect angle, with respect to the target, for each pulse received by this radar. The key to using this technique for ISAR is to know the target's rotational motion which in most cases is unknown. This paper will present a practical motion geometry for the rotational motion of a target, based on a parameterized model. A technique, based on this rotation model, to determine the rotation parameters, using measurements from the radar data itself, will be presented. A practical realization of this technique, using simplifications to the motion model, will be discussed and the effects of this simplification will be described.