The Atmospheric Infrared Sounder (AIRS) is a hyperspectral infrared instrument on the EOS Aqua Spacecraft, launched on May 4, 2002. AIRS has 2378 infrared channels ranging from 3.7 um to 15.4 um and a 13.5 km footprint. The AIRS is a “facility” instrument developed by NASA as an experimental demonstration of advanced technology for remote sensing and the benefits of high resolution infrared spectra to science investigations. AIRS radiances are routinely assimilated by National Weather Prediction Centers worldwide and used by climate scientists for comparison to models and a wide range of process studies. Geophysical products derived from the AIRS include temperature and water vapor profiles, surface, cloud and aerosol properties, and atmospheric trace gas species including CO, CO2, CH4, SO2, and O3. AIRS geophysical products support a wide range of science investigations in support of weather, climate, and atmospheric composition research and applications.

The AIRS instrument has performed exceptionally well during its almost 10 years in orbit without any major failures and is expected to outlast the spacecraft. The cryogenically cooled detector and grating spectrometer combination has proved to be extremely reliable and stable, providing accurate and stable radiances suitable for climate investigations. We examine the AIRS design approach, performance and calibration accuracy, and examine the instrument requirements needed to achieve AIRS performance at 1km horizontal resolution. Improvements are required in optics, detectors, electronics, and data handling as well as advanced retrieval algorithms to handle large data volume and improved resolution and accuracy required to meet future needs.