Evaluation and Correction of Residual Motion Error in Drone SAR Interferometric Images by Using Corner Reflectors

Residual motion errors (RMEs) severely affect interferometric processing in unmanned aerial system (UAS)-borne SAR systems due to limited platform positioning accuracy. This paper proposes an experimental RME estimation and compensation method based on fiducial targets with known positions. The RME is retrieved from the phase difference between measured and simulated range-compressed echoes and injected into the SAR focusing process. Experimental results from repeat-pass flights show a significant reduction of azimuthal phase undulations and millimeter-level motion error estimation accuracy.