Motion error analysis and compensation for airborne formation flying InSAR

Because the stability of plane platform is not good, airborne SAR can not acquire the precise orbit parallelism and velocity as spaceborne SAR. Motion error problem for airborne formation flying InSAR is analyzed here. The plane interval changes (across track baseline changes) can be discussed in three situations: interval increasing, interval decreasing, interval changing according to sine curve. Phase changes with baseline changes are deduced quantiticationally. The simulation result of plane interval changes is given out. It can be concluded that across track baseline changes lead to azimuth slope. The digital relation between across-track baseline error and phase error, height error is concluded by simulation experiment result. The paper presents the method of azimuth slope elimination. Azimuth slope eliminating is adopted in simulation terrain. Two control points are set in topographic area to compensate the phase error of baseline changes. This algorithm can improve the DEM precision for whole area. Even if the plane track is curve, the method in this paper can still compensate most of the motion error.