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Full catalog/TRMM_1B01
TRMM_1B01·v7·dataset

Raw calibrated visible and infrared light (TRMM)

TRMM Visible and Infrared Scanner Calibrated Radiances L1B 1.5 hours V7 (TRMM_1B01) at GES DISC
land NASA GES_DISC Level 1B
In plain English

What it measures. Records how much visible and infrared light the sensor recorded across five channels, carefully calibrated and tagged with its location for every pixel of each scan.

How it's made. Comes from the Visible and Infrared Scanner on NASA's TRMM satellite, converting the instrument's raw counts into calibrated light values using regular reference views of space, the sun, and an onboard blackbody.

How & where you'd use it. A low-level building-block input: it underpins higher-level cloud and rainfall products, so most users work with those finished products rather than these raw calibrated radiances.

What's measured

SPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › INFRARED IMAGERY › RADIANCE @ 1.6UMSPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › INFRARED IMAGERY › RADIANCE @ 3.75UMSPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › INFRARED RADIANCESPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › SENSOR COUNTSSPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › THERMAL INFRARED › RADIANCE @ 10.8UMSPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › THERMAL INFRARED › RADIANCE @ 12.0UMSPECTRAL/ENGINEERING › PLATFORM CHARACTERISTICS › ATTITUDE CHARACTERISTICSSPECTRAL/ENGINEERING › SENSOR CHARACTERISTICS › VIEWING GEOMETRY › SATELLITE LOCAL ZENITH ANGLESPECTRAL/ENGINEERING › VISIBLE WAVELENGTHS › SENSOR COUNTSSPECTRAL/ENGINEERING › VISIBLE WAVELENGTHS › VISIBLE IMAGERY › RADIANCE @ 0.63UMSPECTRAL/ENGINEERING › VISIBLE WAVELENGTHS › VISIBLE RADIANCE

Coverage & cadence

  • Time span1997-12-20 → 2014-03-21
  • Measured byTRMM (VIRS)
  • Processing levelLevel 1B
  • Spatial extent-180, -38, 180, 38
  • StatusCOMPLETE

What you can do with it

  • Track deforestation, fire scars and land-cover change
  • Monitor crop and vegetation health (NDVI/EVI)
  • Map how built-up vs. green an area is over time
Official description

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

Get the data

trmm_1b01_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="TRMM_1B01",
    version="7",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from GES_DISC
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.