Earth Data School
About
Full catalog/ALTIKA_SARAL_L2_OST_XOGDR
ALTIKA_SARAL_L2_OST_XOGDR·vf·dataset

Sea surface height ups and downs, near-real-time (SARAL)

SARAL Near-Real-Time Value-added Operational Geophysical Data Record Sea Surface Height Anomaly
ocean NASA POCLOUD Level 2 netCDF-4
In plain English

What it measures. How much the sea surface rises or falls compared to its average level, delivered quickly within hours of measurement, along with wind speed over the ocean.

How it's made. Measured by the Ka-band AltiKa radar altimeter on the French-Indian SARAL satellite, with its orbit fine-tuned against the Jason-2 mission for better accuracy.

How & where you'd use it. Sea surface height reveals ocean currents, eddies, and sea level changes. The fast near-real-time delivery makes it useful for timely ocean and weather monitoring.

What's measured

OCEANS › SEA SURFACE TOPOGRAPHY › SEA SURFACE HEIGHT › NONEOCEANS › OCEAN WAVES › SIGNIFICANT WAVE HEIGHT › NONE

Coverage & cadence

  • Time span2020-03-18 → ongoing
  • Measured bySARAL (ALTIKA Altimeter)
  • Processing levelLevel 2
  • Spatial extent-180, -82, 180, 82
  • FormatsnetCDF-4
  • StatusACTIVE

What you can do with it

  • Watch sea-surface temperature and marine heatwaves
  • Spot algal blooms and ocean-colour shifts
  • Support fisheries and coastal monitoring
Official description

These data are near-real-time (NRT) (within 7-9 hours of measurement) sea surface height anomalies (SSHA) from the AltiKa altimeter onboard the Satellite with ARgos and ALtiKa (SARAL). SARAL is a French(CNES)/Indian(SARAL) collaborative mission to measure sea surface height using the Ka-band AltiKa altimeter and was launched February 25, 2013. The major difference between these data and the Operational Geophysical Data Record (OGDR) data produced by the project is that the orbit from SARAL has been adjusted using SSHA differences with those from the OSTM/Jason-2 GPS-OGDR-SSHA product at inter-satellite crossover locations. This produces a more accurate NRT orbit altitude for SARAL with accuracy of 1.5 cm (RMS), taking advantage of the 1 cm (radial RMS) accuracy of the GPS-based orbit used for the OSTM/Jason-2 GPS-OGDR-SSHA product. This dataset also contains all data from the project (reduced) OGDR, and improved altimeter wind speeds and sea state bias correction. More information on the SARAL mission can be found at: http://www.aviso.oceanobs.com/en/missions/current-missions/saral.html

Get the data

altika_saral_l2_ost_xogdr_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="ALTIKA_SARAL_L2_OST_XOGDR",
    version="f",
    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 POCLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.