Earth Data School
About
Full catalog/TRMM_1B11
TRMM_1B11·v7·dataset

Raw microwave brightness over the tropics (TRMM)

TRMM Microwave Imager Calibrated Radiances L1B 1.5 hours V7 (TRMM_1B11) at GES DISC
land NASA GES_DISC Level 1B
In plain English

What it measures. Raw measurements of how much microwave energy the tropics emit, expressed as brightness temperatures (how warm surfaces and clouds look to the sensor) across several microwave frequencies.

How it's made. Calibrated radiances from the TRMM Microwave Imager, converted from raw instrument counts to brightness temperatures with basic corrections, but without beam-pattern correction or averaging.

How & where you'd use it. A low-level input used to study tropical rainfall and storms; note the makers point users to a newer GPM-format version, and most people use higher-level rainfall products derived from it.

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 span1997-12-07 → 2015-04-08
  • Measured byTRMM (TMI)
  • 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

The new version of these data is in GPM-like format (consistent with the GPM Microwave Imager data format), and can be found under the name GPM_1BTMI (search by keyword GPM_1BTMI). This dataset contains TRMM Micrwave Imager (TMI) L1B calibrated radiances in terms of Brightness Temperatures. The TMI calibration algorithm (1B11) converts the radiometer counts to antenna temperatures by applying a linear relationship of the form Ta = c1 + c2 x count. The coefficients are provided by the instrument contractor. Antenna temperatures are corrected for cross-polarization and spill over to produce brightness temperatures (Tb), but no antenna beam pattern correction or sample to pixel averaging are performed. Temperatures are provided at 104 scan positions for the low frequency channels and 208 scan positions at 85 GHz. There are four samples per pixel (3 -dB beamwidth) at 10 GHz, two samples at 19, 22, and 37 GHz, and one sample per pixel for the 85 GHz. Data Flow Description 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: 760 km; Horizontal Resolution: 4.4 km Post-Boost (after 24 August 2001): Temporal Resolution: 92.5 min/orbit ~ 16 orbits/day; Swath Width: 878 km; Horizontal Resolution: 5.1 km

Get the data

trmm_1b11_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="TRMM_1B11",
    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.