Time space transform based array error calibration for dual-channel SAR

Multichannel synthetic aperture radar has been widely studied to realize high resolution wide swath imaging; however, the mismatch between channels should be compensated before signal reconstruction. A time-space transform (TST) based auto-calibration method of estimating phase difference in a dual channel system is presented. By means of TST processing, signal subspace and noise subspace are separated, thus the eigenstructure-based auto-calibration method can be applied to obtain an estimate of phase errors. In addition, correlation processing in the spatial frequency domain is proposed to estimate range delay mismatch. Processed results of experimental dual channel airborne data confirm the validity of the methods.