Introduction to a new wide area sar mode using the F-SCAN principle

High Resolution Wide Swath Imaging (HRWS) with spaceborne SAR systems has received major attention over the recent years [1]-[6]. The favored concepts embark on multiple phase centers distributed in both azimuth and elevation direction using Digital Beamforming (DBF) techniques. Whilst the displaced phase center technique aims at improved azimuth resolution at reduced PRF the multiple phase centers in elevation aim at improved signal to noise by using the high gain pencil beam scanning on receive (SCORE) over the target area whilst illuminating the swath with a broad beam pattern on transmit. A highly interesting alternative to the SCORE based on DBF exists with a much lower hardware complexity by exploitation of an analogue frequency scanning antenna sweeping over the target area. This approach offers a couple of unique features not obtainable by the SCORE technique such as inherent pulse compression, excellent signal to noise performance, inherent impulse response sidelobe suppression and overhead free data sampling at greatly reduced need of transmit peak power.