EOS-1 (Earth Observation Satellite), also known as RISAT-1 (Radar Imaging Satellite-1), is a satellite developed by the Indian Space Research Organisation (ISRO).  This satellite was launched by ISRO on 7 November 2020 at SHAR Centre, Sriharikota, India and has a mission life of 2 years. This mission was carried out in PSLV-C49 launch vehicle and has a mass of 615 Kg.

The primary purpose of EOS-1/RISAT-1 is all-weather, day-and-night Earth observation using synthetic aperture radar (SAR) technology. SAR allows the satellite to penetrate through clouds, vegetation, and darkness to provide clear images of the Earth's surface, making it particularly useful for applications such as agriculture, forestry, disaster management, and defense.

EOS-1/RISAT-1 is equipped with a C-band SAR instrument capable of capturing high-resolution radar images of the Earth's surface. The satellite's SAR instrument can operate in different imaging modes, including spot, strip, and mosaic modes, with varying resolutions and coverage areas.