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Full catalog/SWOT_L2_NALT_IGDR_2.0
SWOT_L2_NALT_IGDR_2.0·v2.0·dataset

Sea and lake surface height, interim (SWOT altimeter)

SWOT Level 2 Nadir Altimeter Interim Geophysical Data Record with Waveforms
ocean NASA POCLOUD Level 2 netCDF-4
In plain English

What it measures. The height of the sea and lake surface, plus wave height and wind speed, measured along the track directly beneath the satellite.

How it's made. Collected by the Poseidon-3C nadir altimeter on the NASA-CNES SWOT mission. This is the interim version, processed with preliminary orbit information and delivered within about a day and a half.

How & where you'd use it. Sea surface height reveals currents and sea level change, and SWOT also maps inland water bodies. The interim label means it is an early-release product later refined into final records.

What's measured

OCEANS › SEA SURFACE TOPOGRAPHY › SEA SURFACE HEIGHTOCEANS › OCEAN WAVES › SIGNIFICANT WAVE HEIGHTOCEANS › SEA SURFACE TOPOGRAPHY › DYNAMIC TOPOGRAPHY › ABSOLUTE DYNAMIC TOPOGRAPHYOCEANS › SEA SURFACE TOPOGRAPHY › DYNAMIC TOPOGRAPHY › MEAN DYNAMIC TOPOGRAPHYOCEANS › SEA SURFACE TOPOGRAPHY › MEAN SEA SURFACEOCEANS › SEA SURFACE TOPOGRAPHY › SEA LEVEL › MEAN SEA LEVELOCEANS › SEA SURFACE TOPOGRAPHY › SEA LEVEL › SEA LEVEL ANOMALYOCEANS › SEA SURFACE TOPOGRAPHY › SEA SURFACE HEIGHT › SEA SURFACE HEIGHT ANOMALY (SSHA)OCEANS › SEA SURFACE TOPOGRAPHY › SEA SURFACE SLOPE

Coverage & cadence

  • Time span2022-12-16 → ongoing
  • Measured bySWOT (Jason-class Altimeter, AMR)
  • Processing levelLevel 2
  • Spatial extent-180, -77.6, 180, 77.6
  • FormatsnetCDF-4
  • StatusSUPERSEDED

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

The SWOT Level 2 Nadir Altimeter Interim Geophysical Data Record (IGDR) Version 1.0 dataset produced by the Surface Water and Ocean Topography (SWOT) mission provides sea surface height, significant wave height and wind speed measurements from the Poseidon-3C nadir altimeter, a Jason-class dual frequency (Ku/C) altimeter. SWOT is a joint mission between NASA and CNES that launched on December 16, 2022. It aims to measure ocean surface topography with unprecedented resolution and accuracy, as well as map inland water bodies globally. The IGDR dataset consists of discrete measurements along the nadir track with sampling resolutions of approximately 6-km and 300-m at 1Hz and 20Hz, respectively. The data were processed using the Medium-accuracy (preliminary) Orbit Ephemeris (MOE) and preliminary values for certain auxiliary data. The IGDR data are distributed as one file per half orbit in netCDF-4 file format with a nominal latency of < 1.5 days. This collection is the parent collection to the following sub-collections: https://podaac.jpl.nasa.gov/dataset/SWOT_L2_NALT_IGDR_SSHA_2.0 https://podaac.jpl.nasa.gov/dataset/SWOT_L2_NALT_IGDR_GDR_2.0 https://podaac.jpl.nasa.gov/dataset/SWOT_L2_NALT_IGDR_SGDR_2.0

Get the data

swot_l2_nalt_igdr_2.0_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="SWOT_L2_NALT_IGDR_2.0",
    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 POCLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.