An effective autofocus algorithm for ISAR imaging

Motion compensation is a key step in inverse synthetic aperture radar (ISAR) imaging. The paper first sets up the array model for ISAR imaging that clearly demonstrates the principle and possible methods for initial phase error calibration. An effective autofocus method called the calibrating source iteration algorithm (CASIA) is then presented to calibrate the initial phase errors. Finally, the real measured ISAR data of a flying aircraft are processed to test the performance of the CASIA and the imaging results confirm its validity.