Abstract: The Atmospheric Infrared Sounder (AIRS) is a facility instrument aboard the second Earth Observing System (EOS) polar-orbiting platform, EOS Aqua. In combination with the Advanced Microwave Sounding Unit (AMSU) and the Humidity Sounder for Brazil (HSB), AIRS constitutes an innovative atmospheric sounding group of visible, infrared, and microwave sensors. AIRS data will be generated continuously. ... Global coverage will be obtained twice daily (day and night) on a 1:30pm sun synchronous orbit from a 705-km altitude.
The AMSU-A level 1B data set contains AMSU-A calibrated and geolocated brightness temperatures in degrees Kelvin. This data set is generated from AMSU-A Level 1A digital numbers (DN), including 15 microwave channels in the 50 - 90 GHz and 23 - 32 GHz regions of the spectrum. A day's worth of data is divided into 240 scenes each of 6 minute duration. An AMSU-A scene contains 30 cross-track footprints in each of 45 along-track scanlines, for a total of 45 x 30 = 1350 footprints per scene. The AMSU-A is co-aligned with the AIRS instrument onboard the Aqua platform so that successive blocks of 3 x 3 AIRS footprints are contained within the AMSU-A footprint.
AMSU-A is primarily a temperature sounder that provides atmospheric information in the presence of clouds, which can be used to correct the AIRS infrared measurements for the effects of clouds. This is possible because non-precipitating clouds are for the most part transparent to microwave radiation, in contrast to visible and infrared radiation which are strongly scattered and absorbed by clouds. Combined with simultaneous measurements from the AIRS and HSB instruments, the calibrated AMSU-A brightness temperatures will also be used to initialize the surface temperature and atmospheric temperature profile required for the retrieval of the final AIRS geophysical products.
(The Shortname for this product is AIRABRAD_NRT).
Coverage: Global, Twice Daily (Daytime and Nighttime) Resolution: 40.5 km IFOV at nadir Spectral Range: AMSU-A1: 13 channels from 50 - 90 GHz AMSU-A2: 2 channels from 23 - 32 GHz
Access the AIRS/Aqua Near Real Time (NRT) Level 1B AMSU (A1/A2) geolocated and calibrated brightness temperatures data by FTP. User registration is required. Register for a username and password at the Land Atmosphere Near real-time Capability for EOS (LANCE) web site (https://earthdata.nasa.gov/urs/register).
AIRS home page at NASA/JPL. General information on the AIRS instrument suite, algorithms, and other AIRS-related activities can be found. The Atmospheric Infrared Sounder (AIRS) instrument suite is designed to measure the Earth's atmospheric water vapor and temperature profiles on a global scale. It is comprised of a space-based hyperspectral infrared instrument (AIRS) and two multichannel microwave instruments, the Advanced Microwave Sounding Unit (AMSU-A) and the Humidity Sounder for Brazil (HSB).
AIRS data support home page at Goddard Earth Sciences Data Information and Service Center/Distributed Active Archive Center (GES DISC DAAC). Online documentation, software to read, visualize and analyze AIRS data and data access information are available from this web site.
Data are expected to be available from the GSFC Earth Sciences (GES) Distributed Active ... Archive Center (DAAC) about one year after launch. The DAAC Science Team will provide regular updates regarding data product releases in the future.