TRMM Visible and Infrared Scanner Calibrated Radiances L1B 1.5 hours V7 (TRMM_1B01) at GES DISC

This TRMM Visible and Infrared Scanner (VIRS) Level 1B Calibrated Radiance Product (1B01) contains calibrated radiances and auxiliary geolocation information from the five channels of the VIRS instrument, for each pixel of each scan. The data are stored in the Hierarchical Data Format (HDF), which includes both core and product specific metadata applicable to the VIRS measurements. A file contains a single orbit of data with a file size of about 95 MB. The EOSDIS "swath" structure is used to accommodate the actual geophysical data arrays. There are 16 files of VIRS 1B01 data produced per day.

For channels 1 and 2, Level 1B radiances are derived from the Level 1A (1A01) sensor counts by computing calibration parameters (gain and offset) derived from the counts registered during space and solar and/or lunar views. New calibration parameters are produced every one to four weeks. Channels 3, 4, and 5 are calibrated using the internal blackbody and the space view. These calibration parameters, together with a quadratic term determined pre-launch, are used to generate a counts vs. radiance curve for each band, which is then used to convert the earth-view pixel counts to spectral radiances.

Geolocation and channel data are written out for each pixel along the scan, whereas the time stamp, scan status (containing scan quality information), navigation, calibration coefficients, and solar/satellite geometry are specified on a per-scan basis. There are in general 18026 scans along the orbit pre-boost and 18223 post-boost, with each scan consisting of 261 pixels. The scan width is about 720 km pre-boost and 833 km post-boost.

Changes in horizontal resolution resulting from the TRMM boost that occurred on 24 August 2001:

Pre-Boost (before 7 August 2001): Temporal Resolution: 91.5 min/orbit ~ 16 orbits/day; Swath Width: 720 km; Horizontal Resolution: 2.2 km

Post-Boost (after 24 August 2001): Temporal Resolution: 92.5 min/orbit ~ 16 orbits/day; Swath Width: 833 km; Horizontal Resolution: 2.4 km

Data and Resources

Additional Info

Field Value
Maintainer ANDREY SAVTCHENKO
Last Updated February 18, 2025, 23:57 (UTC)
Created February 18, 2025, 23:57 (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 Tropical Rainfall Measuring Mission (TRMM). 2011-07-01. TRMM_1B01. TRMM Visible and Infrared Scanner Calibrated Radiances L1B 1.5 hours V7. Greenbelt, MD. 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/TRMM_1B01_7.html.
creator Tropical Rainfall Measuring Mission (TRMM)
graphic-preview-file https://docserver.gesdisc.eosdis.nasa.gov/public/project/Images/TRMM_1B01_7.png
harvest_object_id 363cc885-7d46-49ac-8dfe-e55051ecdd98
harvest_source_id b37e5849-07d2-41cd-8bb6-c6e83fc98f2d
harvest_source_title DNG Legacy Data
identifier C1282110251-GES_DISC
issued 2011-07-01
landingPage https://cmr.earthdata.nasa.gov:443/search/concepts/C1282110251-GES_DISC.html
language {en-US}
metadata_type geospatial
modified 2016-04-20
programCode {026:001}
publisher NASA/GSFC/SED/ESD/GCDC/GESDISC
release-place Greenbelt, MD
resource-type Dataset
series-name TRMM_1B01
source_datajson_identifier true
source_hash 99537769b0cbd2729bb762e34058a042a3e0889ee5dccc237e6503a73caea805
source_schema_version 1.1
spatial -180.0 -38.0 180.0 38.0
temporal 1997-12-20T00:00:00Z/2014-03-21T23:59:59.999Z
theme {TRMM,geospatial}