Processing Multiple SAR Modes With Baseband Azimuth Scaling

This paper presents an efficient phase preserving processor for the focusing of data acquired in three different modes, namely sliding-spotlight, TOPS (Terrain Observation by Progressive Scans) and ScanSAR. Existing approches for the azimuth processing can become inefficient due to the additional processing to overcome the folding in time. In this paper, baseband azimuth scaling is used to perform the azimuth processing in an efficient way. The kernel is exactly the same for the three modes, where the computation of the scaling and rotation vectors is slightly different only for the ScanSAR case. A discussion concerning staring-spotlight is also included. Real data acquired by TerraSAR-X in sliding-spotlight, TOPS and ScanSAR modes are used to validate the processor