Calibration of a high resolution airborne 3D SAR

The potential of across-track interferometric (XTI) synthetic aperture radar (SAR) for producing high resolution 3D imagery has been demonstrated by several airborne systems including EMISAR, the dual frequency, polarimetric, and interferometric SAR developed at the Dept. of Electromagnetic Systems (EMI). In order to achieve a high geodetic fidelity when using such systems operationally, calibration procedures must be applied. Inaccurate navigation data and system parameters as well as system imperfections must be accounted for. This paper presents theoretical models describing the impact of key error contributors on the measured terrain elevation. The models are used in estimating calibration parameters on the bases of distributed targets with known elevation. Finally, the calibration procedure is applied to EMISAR data collected by the Danish Center for Remote Sensing (DCRS), and the stability of the estimated parameters is examined in order to assess the general utility of the procedure.