Airborne L-SAR Imaging Experiment Based on Phase Gradient Autofocus

For lack of high precision inertial measurement system,the L-band SAR system produced by the Institute of Electronics of Chinese Academy of Sciences was badly affected by random phase error induced by motion instability.To refocus these images under this particular condition,a fully data-driven imaging scheme based on phase gradient autofocus was tested.SAR imaging processing for different scene contents,including isolated point-object and distributed-object scenes,were performed to verify this refocusing scheme.The experiments show that the imaging scheme based on phase gradient autofocus can effectively measure and compensate the phase errors,thus obtaining obviously improved airborne L-SAR images in azimuth resolution.The processing results prove the effectiveness of this scheme for fully data-driven high-precision airborne L-SAR imaging.