System Design of HRWS Frequency Scanning SAR for Airborne Applications

High Resolution Wide Swath (HRWS) imaging is a key requirement for future SAR sensors and many topologies for same are being proposed in literature. Frequency scanning SAR (FScan SAR) is one of the promising candidate which along with providing the HRWS imaging capability, keeps the payload hardware simplified. FScan SAR utilizes the frequency dispersion phenomenon of array antennas fed with wide bandwidth chirp signals to provide intra-pulse beam scanning which is employed to provide wide swath imaging. As the beam scanning is done within the pulse there is no compromise in azimuth resolution. This paper presents the system design of airborne version of FScan SAR designed to image 30 km swath with 0.5 m ground resolution along with data processing aspects. The proposed system can be used for on demand high resolution imaging and also as a testbed to further enhance the frequency scanning SAR methodology and its processing algorithms. Simulation of one range line using the FScan SAR processing methodology with three point targets is also presented to verify the system performance.