Discussion on the Detection and Correction of Residual Motion Errors in Airborne SAR Interferometry

This paper discusses the detection and correction of residual motion errors, appearing in airborne SAR interferograms due to the lack of precision in the navigation system. Two techniques existing in the literature to detect such errors are presented, highlighting differences and similitudes. The effects of residual motion errors are mainly two: azimuth phase undulations and azimuth registration errors. A new approach, which corrects both effects in one step, is proposed, avoiding the use of interpolations. Additionally, the spectral diversity technique, used to estimate registration errors, is critically analyzed. Airborne L-band repeat-pass interferometric data of the German Aerospace Center (DLR) experimental airborne SAR (E-SAR) is used to validate the method.