Constraints in azimuth resolution by refocusing slowly moving targets from single-look complex SAR vignettes

Abstract:
Accessing the raw data of spaceborne SAR systems is not always possible to refocus blurred SAR signatures of vessels. Instead, the single-look complex (SLC) data is usually more available, but since the vessel motion can shift the Doppler centroid frequency there can be a partial suppression of the target’s spectrum during the windowing in the image formation, limiting the achievable azimuth resolution of the SAR signature. Simulations of slowly moving point-targets and complex vessels with spaceborne SAR sensors (C- and X-band) are carried out to examine the impact of the target motion on the azimuth resolution of its SAR signature.