UCAR-CU CYGNSS Level 3 Soil Moisture Version 1.0

The CYGNSS Level 3 Soil Moisture Product provides volumetric water content estimates for soils between 0-5 cm depth at a 6-hour discretization for most of the subtropics. The data were produced by CYGNSS investigators at the University Corporation for Atmospheric Research (UCAR) and the University Colorado at Boulder (CU), and derive from version 2.1 of the CYGNSS L1 SDR. The soil moisture algorithm uses collocated soil moisture retrievals from SMAP to calibrate CYGNSS observations from the same day. For a given location, a linear relationship between the SMAP soil moisture and CYGNSS reflectivity is determined and used to transform the CYGNSS observations into soil moisture. The data are archived in daily files in netCDF-4 format. Two soil moisture variables report the volumetric water content in units of cm3/cm3. The variable SM_subdaily includes up to four soil moisture estimates per day. Another variable SM_daily provides a daily average. The time series covers the period from March 2017 to present.

Data and Resources

Additional Info

Field	Value
Maintainer	Earthdata Forum
Last Updated	August 18, 2026, 03:41 (UTC)
Created	April 1, 2025, 19:44 (UTC)
accessLevel	public
bureauCode	{026:00}
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harvest_source_id	b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title	Science Discovery Engine
identifier	10.5067/CYGNU-L3SM1
license	https://www.usa.gov/government-works
modified	2026-08-10T22:16:04Z
programCode	{026:000}
publisher	NASA/JPL/PODAAC;UCAR/COSMIC/CDAAC
resource-type	Dataset
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theme	{"Earth Science"}