Abstract: Compared with spaceborne and airborne SAR, DEM extraction using vehicle-mounted SAR data can effectively shorten the update cycle of DEM data and reduce the cost. Due to the variable structure of vehicle-mounted SAR platform, interferometric calibration needs to be repeated, this paper proposes a DEM extraction method of vehicle-mounted interferometric SAR with dual antennas based on a single control point. This method corrects the phase, slope distance and elevation based on the precise coordinate information of a control point and realizes the iterative solution of elevation. It does not need to set up many control points for interferometric calibration, effectively simplifying the field work. The simulation results show that high accuracy of DEM extraction can be guaranteed when the estimation of baseline length reaches the accuracy of mm and the estimation of baseline inclination also reaches a high accuracy. Using vehicle-mounted interferometric SAR data with dual antennas obtained in wuhan, hubei province in 2018,the comparative test of DEM extraction was carried out using this method and multiple control point method based on interferometric calibration. The results show that the elevation error of this method at the checkpoints is 0.301 8 m, and multiple control point method is 0.258 4 m, the DEM results of two methods are highly consistent in the areas with high coherence.

Key words: vehicle-mounted, dual antennas, SAR, DEM, interferometric calibration, single control point