A blind reconstruction of azimuth signal for multichannel HRWS SAR system

Uniformly spaced multichannel system makes it available to achieve the high-resolution and wide-swath (HRWS) synthetic aperture radar (SAR) images. Exact knowledge of the steering vectors is required to reconstruct the azimuth signal. The steering vectors depend upon the pulse repetition frequency (PRF), the platform velocity and the spacing between two adjacent channels. However, the errors existing in these parameters lead to the deterioration of ambiguity suppression. This paper proposes a method to estimate these parameters and obtain the relatively accurate steering vectors. The proposed method exploits the rotational invariance between two signal subspaces. Consequently, a blind reconstruction of azimuth signal can be implemented without knowing the aforementioned parameters. Then we perform experiments based on simulations and real data processing to verify the effectiveness of the proposed method.