Improved channel error calibration method for the azimuth multichannel SAR

In multichannel synthetic aperture radar (SAR) imaging, the orthogonality of the noise subspace and the signal subspace is usually adopted to estimate the channel error. The division of the subspace is based on the number of ambiguity components. In order to avoid the effect of the inaccurate ambiguity components on the subspace division and the channel error estimation, an improved channel error calibration method is proposed, which can lead to the accurate information on the ambiguity components by the spatial spectrum estimation and calibrate the channel error precisely. The real data results validate the method.