IASI main aim was to payload instrument for the purpose of supporting Numerical Weather prediction. It provides information on the vertical structure of the atmospheric temperature and humidity in an unprecedented accuracy of 1 K and a vertical resolution of 1 km, which is needed to decisively improve NWP.

IASI provides infrared soundings of the temperature profiles in the troposphere and lower stratosphere, moisture profiles in the troposphere, and some of the chemical components playing a key role in the climate monitoring, global change and atmospheric chemistry. Data were directly acquired from Eumetsat and are held at the NERC Earth Observation Data Centre (NEODC).