AIRS/Aqua L1B Near Real Time (NRT) Infrared (IR) geolocated and calibrated radiances V005 (AIRIBRAD_NRT) at GES DISC

WARNING: On 2021/09/23 the EOS Aqua executed a Deep Space Maneuver (DSM). In the DSM, the spacecraft is turned such that the normal Earth field of regard is deep space.

The thermal impact of the DSM caused a shift of the centroids of spectral response functions (SRF) of about 1% of the width of the SRF, equivalent to a frequency shift of 9 parts per million. This shift is reflected in the “spectral_freq” parameter (observed frequencies) in the L1b v5 files for each 6 minute granule. The magnitude of the effect on brightness temperatures (BT) depends on the spectral gradient of each channel. Maximum BT shifts are approximately +- 0.5 K, although many channels experience far smaller BT shifts. Approximately 1803 channels have BT shifts of less than 0.1 K and 575 channels are now shifted in BT by more than 0.1 K, while 231 of these channels have BT shifts greater than 0.2 K.

Users of the L1b v5 product who are concerned that these shifts may impact their science investigations and applications are encouraged to switch to the AIRS L1c v6.7.4 product, which, among many other improvements, converts the spectra to a fixed frequency grid. END OF WARNING.

The AIRS Level 1B Near Real Time (NRT) product (AIRIBRAD_NRT_005) differs from the routine product (AIRIBRAD_005) in 2 ways to meet the three hour latency requirements of the Land Atmosphere NRT Capability Earth Observing System (LANCE): (1) The NRT granules are produced without previous or subsequent granules if those granules are not available within 5 minutes, (2) the predictive ephemeris/attitude data are used rather than the definitive ephemeris/attitude. The consequences of these differences are described in the AIRS Near Real Time (NRT) data products document. The Atmospheric Infrared Sounder (AIRS) is a grating spectrometer (R = 1200) 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. The AIRS Infrared (IR) level 1B data set contains AIRS calibrated and geolocated radiances in milliWatts/m^2/cm^-1/steradian for 2378 infrared channels in the 3.74 to 15.4 micron region of t he spectrum. The AIRS instrument is co-aligned with AMSU-A so that successive blocks of 3 x 3 AIRS footprints are contained within one AMSU-A footprint. The AIRIBRAD_NRT_005 products are stored in files (often referred to as "granules") that contain 6 minutes of data, 90 footprints across track by 135 lines along track.

Data and Resources

Additional Info

Field Value
Maintainer ED ESFANDIARI
Last Updated February 19, 2025, 11:23 (UTC)
Created February 19, 2025, 11:23 (UTC)
accessLevel public
bureauCode {026:00}
catalog_@context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
catalog_@id https://data.nasa.gov/data.json
catalog_conformsTo https://project-open-data.cio.gov/v1.1/schema
catalog_describedBy https://project-open-data.cio.gov/v1.1/schema/catalog.json
citation AIRS Science Team/Moustafa Chahine. 2007-07-26. AIRIBRAD_NRT. Version 005. AIRS/Aqua L1B Near Real Time (NRT) Infrared (IR) geolocated and calibrated radiances V005. Greenbelt, MD, USA. Archived by National Aeronautics and Space Administration, U.S. Government, Goddard Earth Sciences Data and Information Services Center (GES DISC). https://disc.gsfc.nasa.gov/datacollection/AIRIBRAD_NRT_005.html. Digital Science Data.
creator AIRS Science Team/Moustafa Chahine
data-presentation-form Digital Science Data
graphic-preview-description Sample image of AIRIBRAD
graphic-preview-file https://docserver.gesdisc.eosdis.nasa.gov/public/project/Images/AIRIBRAD_NRT_005.jpeg
harvest_object_id 975e1966-b1ae-4ffe-af42-ffd4dde5fa19
harvest_source_id b37e5849-07d2-41cd-8bb6-c6e83fc98f2d
harvest_source_title DNG Legacy Data
identifier C1233768982-GES_DISC
issued 2024-11-18
landingPage https://cmr.earthdata.nasa.gov:443/search/concepts/C1233768982-GES_DISC.html
language {en-US}
metadata_type geospatial
modified 2024-11-20
programCode {026:001}
publisher NASA/GSFC/SED/ESD/GCDC/GESDISC
release-place Greenbelt, MD, USA
resource-type Dataset
series-name AIRIBRAD_NRT
source_datajson_identifier true
source_hash 5ef9d8357c81503fec3ca08cd332e4df3d32a88337df10f6c0858971b40ba59e
source_schema_version 1.1
spatial -180.0 -90.0 180.0 90.0
temporal 2015-12-15T00:00:00Z/2024-11-25T00:00:00Z
theme {Aqua,LANCE,geospatial}