The effects of channel imbalances on the azimuth multi-channel SAR

Azimuth multi-channel (AMC) synthetic aperture radar (SAR) is an effective technology to conquer the minimum antenna area constraint and can provide high-resolution and wide-swath (HRWS) SAR images compared with the conventional strip-map SAR. In order to suppress azimuth ambiguity, AMC SAR will face an important problem: channel imbalances estimation and compensation. At first, this paper theoretically analysis the effects of channel imbalances including amplitude imbalance, phase imbalance and range sampling time imbalance (RSTI) on AMC SAR images, where all these channel imbalances will introduce false targets in azimuth, and RSTI will also make a significant influence on the range of SAR images. And then, in order to validate the above result, some simulations based on the parameters are carried out, and the real image acquired by GF-3 is also described. In addition, the intensity, number, and position of false targets are discussed. Finally, this paper makes some conclusions and points out the problems of these results.