The Atmospheric Infrared Sounder, AIRS, is a facility instrument whose goal is to support climate research and improve weather forecasting. Launched into Earth orbit on May 4, 2002 aboard NASA's Aqua satellite, AIRS moves climate research and weather prediction into the 21st century. AIRS is one of six instruments onboard Aqua, which is part of NASA's Earth Observing System of satellites.
AIRS/AMSU/HSB will observe and characterize the entire atmospheric column from the surface to the top of the atmosphere in terms of surface emissivity and temperature, atmospheric temperature and humidity profiles, cloud amount and height, and the spectral outgoing infrared radiation. These data and scientific investigations will answer long-standing questions about the exchange and transformation of energy and radiation in the atmosphere and at Earth's surface.
AIRS, built by BAE SYSTEMS for NASA/JPL, is a cross-track scanning instrument. Its scan mirror rotates around an axis along the line of flight and directs infrared energy from the Earth into the instrument. As the spacecraft moves along, this mirror sweeps the ground creating a scan swath that extends roughly 800 kilometers on either side of the ground track. Within the AIRS instrument the infrared energy is separated into wavelengths. This information is sent from AIRS to the Aqua spacecraft, which relays it to the ground.