Optronic High-Resolution SAR Processing With the Capability of Adaptive Phase Error Compensation

A system design of optronic high-resolution synthetic aperture radar (SAR) processing is proposed in this letter; it has the capability of adaptive phase error compensation. In our system design, SAR raw data are focused optically by phase correction in the two-dimensional frequency domain. The computations of SAR image formation are performed by spatial light modulators and lenses. With the propagation of the laser beam, the imaging results can be captured by the charge-coupled device. The phase error can be estimated from the imaging results, and adaptive phase error compensation is implemented in the optronic processing. Phase error compensation makes the optronic processing robust and flexible; it can be used for both the initial system calibration and the focus quality improvement. Finally, the experimental setup is demonstrated. The entropies of the images with and without phase error compensation are analyzed, which validates its performance on improving the focus quality. The real data results of an airborne SAR and RADARSAT are given.