High-accuracy Doppler measurements for airborne SAR imaging

In this paper, we demonstrate several novel promising techniques and applications of accurate Doppler measurements for airborne SAR imaging. A technique for estimation of the antenna beam orientation angles from Doppler centroid measurements is described. This technique provides an effective clutter-lock. The estimated angles can be used for correction of geometric distortions in SAR images. A multi-look contrast optimization autofocus technique is proposed for an accurate estimation of the Doppler rate via the estimation of the aircraft acceleration. Novel method for retrieving 3D topography of Earth surfaces by using a conventional squint-mode SAR is described. The method is based on high-resolution Doppler centroid measurements with a sub-Hertz accuracy. Experimental results prove the efficiency of these methods.