Internal Calibration and Range Replica Extraction Scheme for Ultra-high Resolution Spaceborne SAR

In order to guarantee the image quality of ultra-high resolution spaceborne SAR, highly precise phase and amplitude response of system is needed via calibration. Since this kind of SAR employs multiple subbands and be equipped with multiple transmit and receive channels to acquire the wider range bandwidth and antenna footprint respectively, it becomes much more complex as compared with conventional SAR. In this paper, we propose a novel internal calibration and range replica extraction scheme to deal with this problem. The calibration loop, module and workflow are provided. And effectiveness of this new scheme is verified by range compression results achieved with an experimental SAR system.