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    • CYGNSS Level 3 Climate Data Record Version 1.0

    Metadata Updated: December 6, 2023

    This dataset contains the Version 1.0 CYGNSS Level 3 Climate Data Record which provides the average wind speed and mean square slope (MSS) on a 0.2x0.2 degree latitude by longitude equirectangular grid obtained from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. The Level 2 Delay Doppler Map (DDM) data are used in the direct processing of the average wind speed and MSS data that are binned on the Level 3 grid. 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. A single netCDF-4 data file is produced for each day of operation with an approximate 2 month latency. The reported sample locations are determined by the specular points corresponding to the Delay Doppler Maps (DDMs). The Version 1.0 CDR represents the first climate-quality release and is a collection of reanalysis products derived from the SDR v2.1 Level 1 data. Calibration accuracy and long term stability are improved relative to the SDR v2.1 using a new trackwise correction algorithm which constrains the average value of the L1 data using MERRA-2 reanalysis wind speeds. 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 v2.1 SDR data processing algorithms. These products also exhibit improved calibration accuracy and stability over SDR v2.1. 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 variations in the transmit power level of the GPS signals measured by the CYGNSS bistatic radar receivers. The SDR v2.1 L1 algorithm assumes a constant GPS transmit power and variations in it can be misinterpreted as variations in the L1 data and in subsequent L2 science data products derived from them. The GPS constellation consists of several different satellite models (a.k.a. block types) and the level of transmit power variation differs between them. The more recent Block IIF models (which account for ~37% of the GPS constellation) have significantly larger variations than the older models and, for this reason, they have been screened out and not used to produce SDR v2.1 L2 or L3 science data products. Trackwise correction eliminates the need for this screening so CDR L2 and L3 data products now include Block IIF samples. It should be noted that the trackwise correction algorithm cannot be successfully applied to all SDR v2.1 L1 data so there is also some loss of samples that were present in SDR v2.1. Overall, there is a significant increase in sampling and improvement in spatial coverage with the CDR products.

    Access & Use Information

    Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    References

    https://doi.org/10.1038/s41598-018-27127-4

    Dates

    Metadata Created Date December 1, 2022
    Metadata Updated Date December 6, 2023

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Graphic Preview

    SOTO (State Of The Ocean) Visualization of CYGNSS Wind Speed

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date December 1, 2022
    Metadata Updated Date December 6, 2023
    Publisher NASA/JPL/PODAAC
    Maintainer
    Identifier C2036882064-POCLOUD
    Data First Published 2019-12-09
    Language en-US
    Data Last Modified 2019-12-09
    Category CYGNSS, geospatial
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Metadata Catalog ID https://data.nasa.gov/data.json
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Citation CYGNSS. 2020-05-22. CYGNSS Level 3 Climate Data Record. Version 1.0. CYGNSS Level 3 Climate Data Record Version 1.0. PO.DAAC. Archived by National Aeronautics and Space Administration, U.S. Government, PO.DAAC. https://doi.org/10.5067/CYGNS-L3C10. https://cygnss.engin.umich.edu/. CYGNSS, PO.DAAC, 2020-05-22, CYGNSS Level 3 Climate Data Record Version 1.0, https://cygnss.engin.umich.edu/.
    Creator CYGNSS
    Graphic Preview Description SOTO (State Of The Ocean) Visualization of CYGNSS Wind Speed
    Graphic Preview File https://soto.podaac.earthdatacloud.nasa.gov/?l=CYGNSS_L3_Wind_Speed_Daily,BlueMarble_ShadedRelief_Bathymetry,Coastlines_15m
    Harvest Object Id ab3c0f46-4482-451c-911d-ef37a98f013f
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://doi.org/10.5067/CYGNS-L3C10
    Metadata Type geospatial
    Old Spatial -180.0 -40.0 180.0 40.0
    Program Code 026:001
    Related Documents https://doi.org/10.1038/s41598-018-27127-4
    Release Place PO.DAAC
    Series Name CYGNSS Level 3 Climate Data Record
    Source Datajson Identifier True
    Source Hash 06379b484e80446e477c9dd63f28182b6ea769a1e0f73b9f6b56de5059eb6017
    Source Schema Version 1.1
    Spatial
    Temporal 2017-03-18T00:00:00Z/2021-02-28T23:59:59.999Z

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