CYGNSS Level 3 Soil Moisture Version 3.2

(CYGNSS_L3_SOIL_MOISTURE_V3.2)
Version3.2
Processing Level3
Start/Stop Date2018-Aug-01 to Present
Short NameCYGNSS_L3_SOIL_MOISTURE_V3.2
DescriptionThe CYGNSS Level 3 Soil Moisture V3.2 dataset is provided by the CYGNSS Science Team of the University of Michigan. It estimates volumetric water content for soils between 0-5 cm depth at a 6-hour discretization for most of the subtropics from the V3.2 reflectivity measurements provided in the CYGNSS L1 SDR dataset (https://doi.org/10.5067/CYGNS-L1X32). 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 Originally made up of a constellation of eight micro-satellites, the observatories provide nearly gap-free Earth coverage using an orbital inclination of approximately 35°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.

The soil moisture retrieval algorithm is an update of the previous version developed by UCAR-CU using a linear regression of CYGNSS angle-normalized effective surface reflectivity trained against collocated SMAP soil moisture during the calibration period 8/1/2018 to 11/15/2023. The data are archived in daily files in netCDF-4 format. Volumetric soil moisture water content in units of cm3/cm3 is provided with two gridding resolutions, 9x9 km and 36x36 km. The variable SM_subdaily contains data reported in six hour intervals. The variable SM_daily provides a daily average. The time series covers the period from August 2018 to present.
DOI10.5067/CYGNU-L3S32
MeasurementLAND SURFACE > SOILS > SOIL MOISTURE/WATER CONTENT
Platform/Sensor
CYGNSS
Platform
Name: Cyclone Global Navigation Satellite System (CYGNSS)
Orbit Period: 94.0 minutes
Inclination Angle: 35.0 degrees
/
DDMI
SENSOR
Name: Delay Doppler Mapping Instrument (DDMI)
Swath Width: 25.0 kilometers
Description: Spacecraft angular distance from orbital plane relative to the Equator.

ProjectCyclone Global Navigation Satellite System (CYGNSS)
Data ProviderPublisher: PO.DAAC
Creator: CYGNSS
Release Place: PO.DAAC
Release Date: 2024-Jun-28
Resource: https://cygnss.engin.umich.edu/

FormatnetCDF-4
Keyword(s)cygnss, level 3, l3, soil moisture, bistatic radar, cosmic, ucar, cu, version 3.2, v3.2, soil, moisture
Questions related to this dataset? Contact podaac@podaac.jpl.nasa.gov
Resolution
Spatial Resolution: 0.3 Decimal Degrees x 0.37 Decimal Degrees
Temporal Resolution: Hourly - < Daily
 
Coverage
Region: GLOBAL
Region: TROPICS
North Bounding Coordinate: 38.15 degrees
South Bounding Coordinate: -38.15 degrees
West Bounding Coordinate: -135 degrees
East Bounding Coordinate: 164 degrees
Time Span: 2018-Aug-01 to Present
Granule Time Span: 2017-Mar-18 to 2025-Feb-06
 
Projection
Projection Type: Lambert Cylindrical Equal Area
Projection Detail: WGS 84 / NSIDC EASE-Grid 2.0 Global
 
NameLong NameUnit
latitudeLatitudedegrees_north
longitudeLongitudedegrees_east
SIGMA_dailyDaily Soil Moisture Sigmacm3 cm-3
SIGMA_subdailySub-daily Soil Moisture Sigmacm3 cm-3
SM_dailyDaily Soil Moisturecm3 cm-3
SM_subdailySub-daily Soil Moisturecm3 cm-3
timeTimedays since 1970-01-01 00:00:00 UTC
timeintervalsstart and stop time for the sub-daily time periodsdays since 2018-08-11 00:00:00 UTC
ANOMALIES
GENERAL DOCUMENTATION
PUBLICATIONS
  • https://doi.org/10.3390/rs12101558
    Chew, C.C., E.E. Small. 'Description of the UCAR/CU Soil Moisture Product'. Remote Sens. 2020, 12, 1558. https://doi.org/10.3390/rs12101558
  • https://doi.org/10.1029/2018GL077905
    Chew, C. C., & Small, E. E. (2018). Soil Moisture Sensing Using Spaceborne GNSSReflections: Comparison of CYGNSS Reflectivity to SMAP Soil Moisture.Geophysical Research Letters, 45(9), 4049-4057.https://doi.org/10.1029/2018GL077905
DATA RECIPE
USER'S GUIDE
DATA CITATION POLICY
Citation is critically important for dataset documentation and discovery. Please cite the data as follows, and cite the reference papers when it is appropriate.
Citation CYGNSS. 2024. CYGNSS Level 3 Soil Moisture Version 3.2. Ver. 3.2. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at https://doi.org/10.5067/CYGNU-L3S32

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For more information see Data Citations and Acknowledgments.

Journal Reference Chew, C.C., E.E. Small.. 2020. Description of the UCAR/CU Soil Moisture Product, Remote Sens, 12, 10. https://doi.org/10.3390/rs12101558

VersionDatasetVersion DateStatus
3.2CYGNSS Level 3 Soil Moisture Version 3.22024-04-10ACTIVE2024-04-10T19:46:00.000Z
1.0UCAR-CU CYGNSS Level 3 Soil Moisture Version 1.02022-04-11ACTIVE2022-04-11T17:36:00.000Z