A novel phase bias estimation method for multichannel HRWS SAR system in azimuth based on RDS analysis

ABSTRACT

Multichannel synthetic aperture radar (SAR) systems in azimuth can realize high-resolution and wide-swath (HRWS) imaging, which has attracted intensive research interests. The azimuth ambiguities caused by non-uniform sampling can be suppressed by digital beamforming technique. However, the presence of inevitable channel errors in the multichannel SAR system deteriorates the performance of ambiguity suppression. Based on the analysis of the characteristics of the multichannel SAR echoes, it was found that phase bias among channels can cause jumping in the reconstructed Doppler spectrum (RDS). This letter presents a novel data-based phase bias estimation method for HRWS SAR system. With the assumption that the splice of echo energy inside the Doppler bandwidth is continuous, there is no jumping in the RDS. The estimation of phase biases in the multichannel HRWS SAR system can be translated into the optimization solution issue. Simulation experiments and real data processing results validated the effectiveness of the proposed method.

Additional information

Funding

This work was supported by the National Key R&D Program of China [2017YFB0502700]; National Natural Science Foundation of China [61871175]; Foundation of Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education [RIMP2020003]; Youth Talent Lifting Project of Henan Province [2019HYTP006]; and College Key Research Project of Henan Province [192102210082].