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Full catalog/GPM_1CF18SSMIS
GPM_1CF18SSMIS·v08·dataset

Raw microwave brightness from space (F18)

GPM SSMIS on F18 Common Calibrated Brightness Temperatures L1C 1.5 hours 12 km V08 (GPM_1CF18SSMIS) at GES DISC
atmosphere NASA GES_DISC Level 1 active
In plain English

What it measures. How much microwave energy the sensor recorded coming off the Earth at several frequencies (called brightness temperature), basically a measure of how the surface and atmosphere look in microwave light.

How it's made. Raw, carefully calibrated readings from the SSMIS microwave instrument on the DMSP F18 satellite, organized into swaths along the satellite's path.

How & where you'd use it. A building-block input mainly used to derive higher-level products like precipitation; most people use it through those rather than directly.

What's measured

ATMOSPHERE › ATMOSPHERIC WATER VAPORATMOSPHERE › PRECIPITATIONSPECTRAL/ENGINEERING › MICROWAVE › BRIGHTNESS TEMPERATURE

Coverage & cadence

  • Time span2009-12-31 → ongoing
  • Measured byDMSP 5D-3/F18 (SSMIS)
  • Processing levelLevel 1
  • Spatial extent-180, -90, 180, 90
  • StatusACTIVE

What you can do with it

  • Map air pollutants — NO₂, aerosols, ozone
  • Track greenhouse gases and Earth's energy budget
  • Feed weather and air-quality analysis
Official description

Version 08 is the current version of the data set. Older versions will no longer be available and have been superseded by Version 08. All 1C products have a common L1C data structure, simple and generic. Each L1C swath includes scan time, latitude and longitude, scan status, quality, incidence angle, Sun glint angle, and the intercalibrated brightness temperature (Tc). One or more swaths are included in a product. The radiometer data are recalibrated to a common basis so that precipitation products derived from them are consistent. 1CSSMIS contains common calibrated brightness temperature from the SSMIS passive microwave instruments flown on the DMSP satellites. Swath S1 has 3 low frequency channels (19V 19H 22V). Swath S2 has 2 low frequency channels (37V 37H). Swath S3 has 4 high frequency channels (150H 183+/-1H 183+/-3H 183+/-7H). S4 has 2 high frequency channels (91V 91H). All the above frequencies are in GHz. Earth observations for all four swaths are taken during a 144o segment of the instrument rotation when SSMIS scans in the direction of foreward satellite motion. We define the spacecraft vector (v) at the center of this segment. SSMIS geometric footprints are: 42.4x70.1 km (19.35, and 22.235), 27.5x44.2 km (37-GHz), 17.5x25.8 km (50.3, 52.8, 53.596, 54.4, 55.5, 57.29, 59.4, 60, and 63-GHz),13.1x14.4 km (91.665, 150, 183-GHz). GPM Project cross-calibrates channels at spatial sampling: 19.35-22.235 GHz and 37 GHz at (12x25 km) (cross-track x along-track at forward bore sight) ; 91.665 and 150-183 GHz at (12x12 km).

Get the data

gpm_1cf18ssmis_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="GPM_1CF18SSMIS",
    version="08",
    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.