CYGNSS Level 2 Science Data Record Version 3.0
DOI10.5067/CYGNS-L2X30
Short NameCYGNSS_L2_V3.0
DescriptionThis dataset contains the Version 3.0 CYGNSS Level 2 Science Data Record which provides the time-tagged and geolocated average wind speed (m/s) and mean square slope (MSS) with 25x25 kilometer resolution from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. This version supersedes Version 2.1; https://doi.org/10.5067/CYGNS-L2X21. The reported sample locations are determined by the specular points corresponding to the Delay Doppler Maps (DDMs). A subset of DDM data used in the direct processing of the average wind speed and MSS is co-located inside of the Level 2 data files. Only one netCDF data file is produced each day (each file containing data from up to 8 unique CYGNSS spacecraft) with a latency of approximately 6 days (or better) from the last recorded measurement time. Here is a summary of processing changes reflected in the v3.0 data: 1) the changes to calibration and validation of the Level 1 Normalized Bistatic Radar Cross Section (NBRCS) necessitated updates to the Geophysical Model Functions (GMFs) used to retrieve wind speed; 2) the GMF for fully developed seas (FDS) conditions was generating using matchups between NBRCS measurements and coincident wind speeds produced by NASAs Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) reanalysis model; 3) the GMF for young seas with limited fetch (YSLF) was generated using matchups between NBRCS and coincident wind speeds produced by NOAAs Hurricane Weather Research and Forecast (HWRF) System; 4) YSLF wind speed is a tapered linear combination of wind speeds derived from the FDS and YSLF GMFs, where the taper gives more weight to FDS at low wind speeds and more to YSLF at high wind speeds and accounts for the transition from FDS to YSLF sea state conditions near cyclonic storms; 5) re-introduces measurements using transmissions from previously discarded GPS satellite block types; in prior versions, Block II-F was completely discarded due to large variations in GPS transmit power. The real time transmit power monitoring and correction implemented in Level 1 v3.0 data now allows Block II-F signals to be used.
Version3.0
Dataset TypeACTIVE
MeasurementSPECTRAL/ENGINEERING > RADAR > RADAR CROSS-SECTION
OCEANS > OCEAN WINDS > SURFACE WINDS
Processing Level2
CoverageRegion: GLOBAL
North Bounding Coordinate: 40 degrees
South Bounding Coordinate: -40 degrees
West Bounding Coordinate: -180 degrees
East Bounding Coordinate: 180 degrees
Time Span: 2018-Aug-01 to Present
Granule Time Span: 2018-Aug-01 to 2021-Aug-03
ResolutionSpatial Resolution: 25 km (Along) x 25 km (Across)
ProjectionProjection Type: Satellite native along-track
Projection Detail: Geolocation information included for each pixel
Ellipsoid: WGS 84
Swath Width25 km
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: 2020-Oct-28
Resource: https://clasp-research.engin.umich.edu/missions/cygnss/

Keyword(s)cygnss, ddm, ddmi, doppler, delay doppler, delay, specular point, wind, winds, wind speed, version 3.0, v3.0, v3
Questions related to this dataset? Contact podaac@podaac.jpl.nasa.gov
GENERAL DOCUMENTATION
USER'S GUIDE
ANOMALIES
PUBLICATIONS
  • https://doi.org/10.1109/TGRS.2016.2541343
    Clarizia, M. P., and C. S. Ruf, 'Wind Speed Retrieval Algorithm for the Cyclone Global Navigation Satellite System (CYGNSS) Mission', IEEE Trans Geosci. Remote Sens., doi:10.1109/TGRS.2016.2541343, 2016.
  • https://doi.org/10.1175/BAMS-D-18-0337.1
    Ruf, C., S. Asharaf, R. Balasubramaniam, S. Gleason, T. Lang, D. McKague, D. Twigg, and D. Waliser, 2019. In-Orbit Performance of the Constellation of CYGNSS Hurricane Satellites. Bull. Amer. Meteor. Soc., 100, 2009 - 2023, https://doi.org/10.1175/BAMS-D-18-0337.1.
  • https://doi.org/10.1109/JSTARS.2018.2833075
    Ruf, C., R. Balasubramaniam, 'Development of the CYGNSS Geophysical Model Function for Wind Speed', IEEE J. Sel. Topics Appl. Earth Obs. Remote Sens., doi: 10.1109/JSTARS.2018.2833075, 2018.
  • https://doi.org/10.1175/BAMS-D-14-00218.1
    Ruf, C., R. Atlas, P. Chang, M. Clarizia, J. Garrison, S. Gleason, S. Katzberg, Z. Jelenak, J. Johnson, S. Majumdar, A. O'Brien, D. Posselt, A. Ridley, R. Rose, V. Zavorotny (2015). New Ocean Winds Satellite Mission to Probe Hurricanes and Tropical Convection. Bull. Amer. Meteor. Soc., doi:10.1175/BAMS-D-14-00218.1.
DATA CITATION POLICY
Citation CYGNSS. 2020. CYGNSS Level 2 Science Data Record Version 3.0. Ver. 3.0. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at https://doi.org/10.5067/CYGNS-L2X30

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For more information see Data Citations and Acknowledgments.

Journal Reference Ruf, C., S. Asharaf, R. Balasubramaniam, S. Gleason, T. Lang, D. McKague, D. Twigg, and D. Waliser, 2019. In-Orbit Performance of the Constellation of CYGNSS Hurricane Satellites. Bull. Amer. Meteor. Soc., 100, 2009 - 2023, https://doi.org/10.1175/BAMS-D-18-0337.1.

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VersionDatasetVersion DateStatus
3.0CYGNSS Level 2 Science Data Record Version 3.02020-09-22ACTIVE1600796085416
2.1CYGNSS Level 2 Science Data Record Version 2.12018-05-14ACTIVE1526337518292
2.0CYGNSS Level 2 Science Data Record Version 2.02017-10-27RETIRED1509074651180
1.1CYGNSS Level 2 Science Data Record Version 1.12017-06-09RETIRED1496969012015
1.0CYGNSS Level 2 Science Data Record Version 1.02016-05-12RETIRED1463079879661