An Earth-observation instrument of the European Space Agency that produces infrared images at a resolution of 1 km. Launched on European Remote-Sensing Satellites, the instruments scan the land, oceans, and atmosphere, contributing to the knowledge of climate studies and climate change. ATSR-1 was aboard ERS-1 (launched in 1991) and ATSR-2 on ERS-2 (launched in 1995). The advanced along-track scanning radiometer (AATSR) was developed for the Envisat.