CYGNSS Level 2 Climate Data Record Version 1.1

(CYGNSS_L2_CDR_V1.1)
Version1.1
Processing Level2
Start/Stop Date2018-Aug-01 to Present
Short NameCYGNSS_L2_CDR_V1.1
DescriptionThis dataset contains the Version 1.1 CYGNSS Level 2 Climate 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. 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 1 to 2 months from the last recorded measurement time. The Version 1.1 CDR represents is a collection of reanalysis products derived from the SDR v3.0 Level 1 data (https://doi.org/10.5067/CYGNS-L1X30 ). Calibration accuracy and long term stability are improved relative to SDR v3.0 (https://doi.org/10.5067/CYGNS-L2X30 ) using the same trackwise correction algorithm as was used by CDR v1.0 (https://doi.org/10.5067/CYGNS-L2C10 ), which was derived from SDR v2.1 Level 1 data (https://doi.org/10.5067/CYGNS-L1X21 ). Details of the algorithm are provided in the Trackwise Corrected CDR Algorithm Theoretical Basis Document. CDR Level 2 and 3 products (ocean surface wind speed, mean square slope, and latent and sensible heat flux) are generated from the CDR L1 data using the v3.0 SDR data processing algorithms. These products also exhibit improved calibration accuracy and stability over SDR v3.0. Trackwise correction is applied to the two primary CYGNSS L1 science data products, the normalized bistatic radar cross section (NBRCS) and the leading edge slope of the Doppler-integrated delay waveform (LES). The correction compensates for small errors in the Level 1 calibration, due e.g. to uncertainties in the GPS transmitting antenna gain patterns and the CYGNSS receiving antenna gain patterns. CDR v1.1 does not include a Young Seas with Limited Fetch (YSLF) wind speed product and investigators requiring wind speed measurements in and near the inner core of tropical cyclones should use the SDR v3.0 YSLF wind speed product. A YSLF wind speed product is omitted because the trackwise correction algorithm, which constrains the average value of the L1 data using MERRA-2 reanalysis wind speeds, is inherently biased toward fully developed sea state conditions. The constraint improves wind speed retrieval performance in fully developed seas but produces underestimates in YSLF conditions. It should also be noted that the trackwise correction algorithm cannot be successfully applied to all SDR v3.0 L1 data so there is also some loss of samples that were present in SDR v3.0.
DOI10.5067/CYGNS-L2C11
MeasurementOCEANS > OCEAN WINDS > SURFACE WINDS
OCEANS > OCEAN WINDS > SURFACE WINDS
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: 2021-Feb-05
Resource: https://cygnss.engin.umich.edu/

FormatnetCDF-4
Keyword(s)cygnss, ddm, ddmi, doppler, delay doppler, delay, specular point, wind, winds, wind speed, cdr, climate data record, climate, version 1.1, v1.1
Questions related to this dataset? Contact podaac@podaac.jpl.nasa.gov
Resolution
Spatial Resolution: 25 km (Along) x 25 km (Across)
Temporal Resolution: Hourly - < Daily
 
Coverage
Region: 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 2022-Feb-28
Swath Width: 25 km
 
Projection
Projection Type: Satellite native along-track
Projection Detail: Geolocation information included for each pixel
Ellipsoid: WGS 84
 
DATA RECIPE
ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)
GENERAL DOCUMENTATION
USER'S GUIDE
ANOMALIES
DATA CITATION POLICY
Citation CYGNSS. 2021. CYGNSS Level 2 Climate Data Record Version 1.1. Ver. 1.1. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at https://doi.org/10.5067/CYGNS-L2C11

Download Citation
RIS XML JSON-LD

For more information see Data Citations and Acknowledgments.

Journal Reference Ruf, C. S., Chew, C., Lang, T., Morris, M. G., Nave, K., Ridley, A., and Balasubramaniam, R.. 2018. A New Paradigm in Earth Environmental Monitoring with the CYGNSS Small Satellite Constellation, Scientific Reports, 8. https://doi.org/10.1038/s41598-018-27127-4

VersionDatasetVersion DateStatus
1.0CYGNSS Level 2 Climate Data Record Version 1.02020-03-23COMPLETE2020-03-23T22:09:13.069Z
1.1CYGNSS Level 2 Climate Data Record Version 1.12020-12-16ACTIVE2020-12-16T21:02:46.456Z