TRANSLATIONAL MOTION COMPENSATION IN ISAR IMAGE-PROCESSING

In inverse synthetic aperture radar (ISAR) imaging, the target rotatio nal motion with respect to the radar line of sight contributes to the imaging ability, whereas the translational motion must be compensated out. This paper presents a novel two-step approach to translational mo tion compensation using an adaptive range tracking method for range bi n alignment and a recursive multiple-scatterer algorithm (RMSA) for si gnal phase compensation. The initial step of RMSA is equivalent to the dominant-scatterer algorithm (DSA). An error-compensating point sourc e is then recursively synthesized from the selected range bins, where each contains a prominent scatterer, Since the clutter-induced phase e rrors are reduced by phase averaging, the image speckle noise can be r educed significantly. Experimental data processing for a commercial ai rcraft and computer simulations confirm the validity of the approach.