Earth Data School
About
Full catalog/gnssro_cosmic1_romsaf_l2a
gnssro_cosmic1_romsaf_l2a·v2.0·dataset

Atmosphere bending GPS signals to reveal temperature (COSMIC-1)

GNSS radio occultation L2A bending angle, refractivity, and dry pressure for COSMIC1 as contributed by ROMSAF, version 2.0 (gnssro_cosmic1_romsaf_l2a)
atmosphere NASA GES_DISC Level 2
In plain English

What it measures. This captures how Earth's atmosphere bends radio signals from GPS-type satellites as they pass through the air, along with derived quantities like refractivity and dry pressure. The bending reveals atmospheric properties such as temperature, pressure, and water vapor.

How it's made. It comes from the COSMIC-1 mission's radio occultation measurements, processed by the ROMSAF facility, with each file covering a single signal passing through the atmosphere.

How & where you'd use it. Widely used to improve weather forecasts and study the atmosphere, because the technique gives accurate, well-distributed measurements around the globe.

What's measured

ATMOSPHERE › ALTITUDE › GEOPOTENTIAL HEIGHTATMOSPHERE › ALTITUDEATMOSPHERE › RADIO OCCULTATION PROFILES › BENDING ANGLEATMOSPHERE › RADIO OCCULTATION PROFILES › REFRACTIVITY

Coverage & cadence

  • Time span2006-04-22 → 2016-12-31
  • Measured byCOSMIC/FORMOSAT-3 (GNSS)
  • Processing levelLevel 2
  • Spatial extent-180, -90, 180, 90
  • StatusCOMPLETE

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

This dataset provides Global Navigation Satellite System (GNSS) Radio Occultation (RO) Bending Angle, Refractivity, and Dry Pressure data from the Constellation Observing System for Meteorology Ionosphere & Climate - 1 mission as contributed by the Radio Occultation Meteorology Satellite Application Facilities. Each granule represents a single occultation. GNSS RO is a remote sensing technique that measures the refracted radio signals generated by GNSS satellites and viewed through Earth’s limb. Parameters describing the refraction can be used to infer familiar atmospheric variables such as temperature, pressure and water vapor. The RO technique allows for increased global coverage of temperature and water vapor through the large number of daily observations and as a result plays an important role in the enhancement of Numerical Weather Prediction and other atmospheric-related studies.

Get the data

gnssro_cosmic1_romsaf_l2a_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="gnssro_cosmic1_romsaf_l2a",
    version="2.0",
    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.