High-resolution Spaceborne SAR Processing Using the Decomposed Transfer Function

In this paper a new analytic decomposed transfer function (DTF) for spaceborne SAR (Synthetic Aperture Radar) processing is calculated using the stationary phase approximation and Taylor’s series expansion. The DTF copes with large Doppler centroid variations and executes range cell migration correction, secondary range compression, azimuth compression and higher order effects. A fourth-order (DTF4) and a fifth-order (DTF5) algorithm have been implemented using segmented block processing. It is shown that the DTF4 yields high quality 3-look target responses at azimuth resolution 0.3 m and range resolution 0.5 m at low squint (yaw=0.3º) for X-band. At higher squint (yaw=7.5º) the DTF5 has to be used to obtain adequate image quality.