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    • CYGNSS Level 1 Science Data Record Version 2.1

    Metadata Updated: December 7, 2023

    This Level 1 (L1) dataset contains the Version 2.1 geo-located Delay Doppler Maps (DDMs) calibrated into Power Received (Watts) and Bistatic Radar Cross Section (BRCS) expressed in units of meters squared from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. This version supersedes Version 2.0. Other useful scientific and engineering measurement parameters include the DDM of Normalized Bistatic Radar Cross Section (NBRCS), the Delay Doppler Map Average (DDMA) of the NBRCS near the specular reflection point, and the Leading Edge Slope (LES) of the integrated delay waveform. The L1 dataset contains a number of other engineering and science measurement parameters, including sets of quality flags/indicators, error estimates, and bias estimates as well as a variety of orbital, spacecraft/sensor health, timekeeping, and geolocation parameters. At most, 8 netCDF data files (each file corresponding to a unique spacecraft in the CYGNSS constellation) are provided each day; under nominal conditions, there are typically 6-8 spacecraft retrieving data each day, but this can be maximized to 8 spacecraft under special circumstances in which higher than normal retrieval frequency is needed (i.e., during tropical storms and or hurricanes). Latency is approximately 6 days (or better) from the last recorded measurement time. The Version 2.1 release represents the second science-quality release. Here is a summary of improvements that reflect the quality of the Version 2.1 data release: 1) data is now available when the CYGNSS satellites are rolled away from nadir during orbital high beta-angle periods, resulting in a significant amount of additional data; 2) correction to coordinate frames result in more accurate estimates of receiver antenna gain at the specular point; 3) improved calibration for analog-to-digital conversion results in better consistency between CYGNSS satellites measurements at nearly the same location and time; 4) improved GPS EIRP and transmit antenna pattern calibration results in significantly reduced PRN-dependence in the observables; 5) improved estimation of the location of the specular point within the DDM; 6) an altitude-dependent scattering area is used to normalize the scattering cross section (v2.0 used a simpler scattering area model that varied with incidence and azimuth angles but not altitude); 7) corrections added for noise floor-dependent biases in scattering cross section and leading edge slope of delay waveform observed in the v2.0 data. Users should also note that the receiver antenna pattern calibration is not applied per-DDM-bin in this v2.1 release.

    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/10.1175/BAMS-D-18-0337.1

    Dates

    Metadata Created Date December 1, 2022
    Metadata Updated Date December 7, 2023

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Graphic Preview

    Thumbnail

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date December 1, 2022
    Metadata Updated Date December 7, 2023
    Publisher NASA/JPL/PODAAC
    Maintainer
    Identifier C2251464384-POCLOUD
    Data First Published 2018-05-14
    Language en-US
    Data Last Modified 2018-05-14
    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. 2018-09-21. CYGNSS Level 1 Science Data Record. Version 2.1. CYGNSS Level 1 Science Data Record Version 2.1. PO.DAAC. Archived by National Aeronautics and Space Administration, U.S. Government, PO.DAAC. https://doi.org/10.5067/CYGNS-L1X21. https://cygnss.engin.umich.edu/. CYGNSS, PO.DAAC, 2018-09-21, CYGNSS Level 1 Science Data Record Version 2.1, https://cygnss.engin.umich.edu/.
    Creator CYGNSS
    Graphic Preview Description Thumbnail
    Graphic Preview File https://podaac.jpl.nasa.gov/Podaac/thumbnails/CYGNSS_L1_V2.1.jpg
    Harvest Object Id fb52c92a-9125-404b-b16a-23a2bdec1a40
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://doi.org/10.5067/CYGNS-L1X21
    Metadata Type geospatial
    Old Spatial -180.0 -40.0 180.0 40.0
    Program Code 026:001
    Related Documents https://doi.org/10.1175/BAMS-D-18-0337.1
    Release Place PO.DAAC
    Series Name CYGNSS Level 1 Science Data Record
    Source Datajson Identifier True
    Source Hash a3cb721bcb5c7cbbaf73b7f13b00bc8ebf54336236ec21019939fc03d478cdb0
    Source Schema Version 1.1
    Spatial
    Temporal 2017-03-18T00:00:00Z/2023-02-28T00:00:00Z

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