Based on Minimum-entropy HRWS SAR channel-calibration method

In high-resolution and width-swath (HRWS) synthetic aperture radar (SAR) imaging, the channel-calibration is one key problem for Doppler ambiguity suppression. Because the Doppler ambiguity suppression algorithm is sensitive to the channel phase error, an accurate estimation for the channel phase error becomes a must. In this paper, the channel phase error is estimated using the Minimum-entropy phase adjustment theory. During the estimation, the deramping operation is implemented along azimuth and the deramped SAR image can be gotten. Based on the entropy of deramped SAR image, the channel error phase can be estimated. The performance of the proposed approach is evaluated by the simulation and real measured data, and the effectiveness is demonstrated.