Efficient detection and correction of residual motion errors in airborne SAR interferometry

This paper discusses the detection and correction of residual motion errors in airborne SAR interferograms. They usually appear 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 similarities. The effects of residual motion errors in the final interferogram are mainly two: azimuth phase undulations and azimuth registration errors. A new correction approach is proposed, which corrects both effects in one step, 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.