The COSMO-SkyMed 1-4 (Constellation of Small Satellites for Mediterranean basin Observation) x-band dual-purpose spacecraft series was developed by the Italian space Agency (ASI) in cooperation with the Italian Ministry of defense. All satellites of the group are equipped with a synthetic aperture radar that allows interferometric survey of the earth's surface with ultra-high spatial resolution (better than 1 m on the ground). The peculiarity of these radar satellites is the ability to obtain images of the earth's surface at any visibility, regardless of meteorological conditions at any time of the day. A series of 4 devices-twins provides frequent updating of images, which allows for almost daily operational monitoring, as well as provides the possibility of rapid response in cases of emergency.