Estimation and correction of roll errors in dual antenna interferometric SAR

The paper describes a data driven technique for estimation and correction of roll related interferometric phase errors in data gathered in a single pass from an aircraft-borne interferometric SAR. The data is processed as two independent azimuth looks, and an interferogram generated from each look. The change in aircraft roll angle is inferred from the differential phase between the two looks. In the absence of pitch and yaw motions, this can be integrated to give the roll angle without the need for an inertial navigation unit (INU). Results are presented using real data from the DERA C-band interferometric SAR, and are compared with measurements from an on-board Litton-93 INU. Two cases are presented, one in which the aircraft performed a 5/spl deg/ roll manoeuvre, and another with the aircraft in normal flight. Interferograms are shown before and after roll compensation.