A Novel Channel Error Calibration Algorithm for Multichannel High-Resolution and Wide-Swath SAR Imaging Based on the Oblique Projection

The Azimuth multichannel synthetic aperture radar (SAR) can achieve the high resolution and wide swath (HRWS) imaging of the ground observation scene. However, the inevitable channel phase error will lead to azimuth ambiguities, i.e., the appearance of "ghost" points, which will degrade the SAR imaging quality. To address this issue, a novel channel error calibration method based on the oblique projection is proposed in this article. First, the optimal weight of each Doppler ambiguity component is calculated by the oblique projection. Then, the optimization function is constructed based on the power maximization method, from which the channel phase error can be estimated. Finally, the HRWS-SAR imaging can be precisely accomplished after performing the channel error calibration. The real-measured multichannel SAR data with azimuth ambiguity is provided to validate the proposed method.