An Improved Airborne Multichannel SAR Imaging Method With Motion Compensation and Range-Variant Channel Mismatch Correction

Abstract

To obtain high resolution and wide swath (HRWS) image, the azimuth multi-channel technique has been widely used in synthetic aperture radar (SAR) systems to overcome the contradiction between wide swath and high pulse repetition frequency (PRF). For high image quality, channel mismatch correction is an essential step in multi-channel SAR data imaging. However, in the case of airborne multi-channel SAR, motion errors will severely degrade the performance of channel mismatch correction. To deal with this problem, this paper proposes an improved airborne multi-channel SAR imaging method with motion compensation (MOCO) and range-variant channel mismatch correction. Firstly, motion errors are compensated based on resampling and phase compensation. Then the time delay error and constant gain-phase error between channels are estimated and corrected, followed by range-variant phase error correction based on a novel range-down-sampling method, which reduces the influence of motion errors on channel mismatch correction significantly. Finally, simulated and real data processing results are used to demonstrate the effectiveness of the proposed method.

Sensitivity of back‐projection algorithm (BPA) synthetic aperture radar (SAR) image formation to initial position, velocity, and attitude navigation errors

“…In this field of motion compensation, motion errors are typically considered in the instantaneous sense [18,19]. In other words, at any point in time, a vehicle has a position error that displaces it from the ideal trajectory.…”