The key importance of radar remote sensing for civil applications has been recognized for decades, and enormous scientific and technical developments have been carried out to further improve the SAR sensors and SAR data processing.
In recent years, SAR satellite constellations consisting of two or more satellites are getting the “new normal” in SAR remote sensing. The present availability of the SAR sensor constellations like Cosmo SkyMed, TerraSAR-X/TanDEM-X, and the new Copernicus sensors Sentinel-1A and 1B supply a continuous stream of imagery, offering an unprecedented amount of high quality SAR data, suitable for a variety of applications provided proper data processing methodology are applied.
Future concepts, like a geosynchronous SAR or the use of non-traditional orbits for fast revisiting times over areas of interest are also important concepts for the future development of SAR remote sensing. Therefore, this wide technological availability stimulates methodological advances and innovative concepts, and new applications are opened or the already established ones are benefiting of a sort of second life.