SAR (Synthetic Aperture Radar)

Synthetic aperture radar is an active microwave imager that synthesizes a long virtual antenna from the platform’s motion to achieve fine along-track resolution independent of range. By coherently combining returns as the satellite passes, a meters-to-tens-of-meters antenna behaves like one hundreds of meters long, resolving features to a few meters across swaths of tens to hundreds of kilometers. It images day and night through cloud, reading sea surface roughness, so it detects ships, oil slicks, internal waves, and sea ice. Phase coherence between passes enables InSAR deformation mapping. Sentinel-1, RADARSAT, and ICEYE supply operational maritime SAR.