This invention discloses a
phase compensation method for ship targets using ISAR based on block
phase gradient autofocus. The steps include:
pulse compression; range
cell migration correction; range-oriented block segmentation; block
phase compensation; calculation of the offset between adjacent image blocks; and image block alignment and stitching. This invention performs range-oriented block segmentation of the target echo, overcoming the shortcomings of existing technologies that ignore the spatial variation of rotational
phase error, leading to defocusing in ship imaging, thus improving the accuracy of
phase compensation and achieving
good image focusing effect. Because this invention uses a
phase gradient autofocus algorithm to compensate for the
phase error within each block, and then uses a cross-
correlation method to align and stitch the images of each block region, it overcomes the shortcomings of parameter
estimation methods, such as complexity, time consumption, and poor real-time performance, and has the advantages of simple implementation, high efficiency, and strong real-time performance.