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Full catalog/CYGNSS_L3_UC_BERKELEY_WATERMASK_V3.1
CYGNSS_L3_UC_BERKELEY_WATERMASK_V3.1·v3.1·dataset

Monthly map of where water vs land is (CYGNSS)

UC Berkeley CYGNSS Level 3 Monthly RWAWC Watermask Version 3.1
hydrosphere NASA POCLOUD Level 3 NETCDF
In plain English

What it measures. Monthly maps marking where inland surface water sits versus dry land, at about 1-kilometer detail. Each pixel is labeled as land, water, or no-data/ocean.

How it's made. Derived from the CYGNSS constellation of small satellites; a 'random walker' algorithm turns their signals into a water-versus-land classification each month.

How & where you'd use it. Useful for tracking flooding, wetlands, and seasonal changes in where surface water appears across the land.

What's measured

TERRESTRIAL HYDROSPHERE › SURFACE WATER › SURFACE WATER PROCESSES/MEASUREMENTS

Coverage & cadence

  • Time span2018-08-01 → ongoing
  • Measured byCYGNSS (DDMI)
  • Processing levelLevel 3
  • Spatial extent-180, -37.4, 180, 37.4
  • FormatsNETCDF
  • StatusACTIVE

What you can do with it

  • Follow rainfall, floods and surface-water extent
  • Track soil moisture and the onset of drought
  • Monitor lakes, rivers and groundwater storage
Official description

The CYGNSS Level 3 UC Berkeley Watermask Record Version 3.1 was developed by CYGNSS investigators in the Department of Civil and Environmental Engineering at the University of California, Berkeley. CYGNSS was launched on 15 December 2016, it is a NASA Earth System Science Pathfinder Mission that was launched with the purpose of collecting the first frequent space‐based measurements of surface wind speeds in the inner core of tropical cyclones. Originally made up of a constellation of eight micro-satellites, the observatories provide nearly gap-free Earth coverage using an orbital inclination of approximately 35° from the equator, with a mean (i.e., average) revisit time of seven hours and a median revisit time of three hours. This dataset is derived from version 3.1 of the CYGNSS L1 SDR dataset (https://doi.org/10.5067/CYGNS-L1X31), and provides monthly binary inland surface water classification data at a 0.01-degree (~1x1 kilometer) resolution with a 1-month latency. This product, known as the UC Berkeley Random Walk Algorithm WaterMask from CYGNSS (Berkeley-RWAWC), generates water classification for a given location based on CYGNSS observations combined with a random walker algorithm. The watermask variable includes binary values indicating land (0), surface water (1), and no data/ocean (-99). The data product is archived in monthly files in netCDF-4 format and covers the period from August 2018 to present.

Get the data

cygnss_l3_uc_berkeley_watermask_v3.1_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="CYGNSS_L3_UC_BERKELEY_WATERMASK_V3.1",
    version="3.1",
    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.