CYGNSS Level 1 Science Data Record Version 2.1

Description

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.

Resources

Name Format Description Link
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2F148-0136_ATBD_L1A_DDMCalibration_Rev2_Aug2018_release.pdf
5 https://journals.ametsoc.org%2Fdoi%2F10.1175%2FBAMS-D-14-00218.1
5 https://cygnss.engin.umich.edu%2F
5 https://cygnss.engin.umich.edu%2Fwp-content%2Fuploads%2Fsites%2F534%2F2021%2F06%2FCYGNSS_Handbook_April2016.pdf
5 https://doi.org%2F10.1029%2F2019GL085134
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2F148-0346-6_L1_v2.1_netCDF_Data_Dictionary.xlsx
5 https://podaac.jpl.nasa.gov%2Fforum%2Fviewtopic.php%3Ff%3D16%26t%3D1261
5 https://doi.org%2F10.1109%2FTGRS.2015.2502245
5 https://doi.org%2F10.1175%2FBAMS-D-18-0337.1
5 https://docs.google.com%2Fspreadsheets%2Fd%2F1AFAZanVGDApLSnJQAAdPfOKoJQs0jnB8ZvIuD1Z5mAc%2Fedit%23gid%3D0
5 https://github.com%2Fpodaac%2Fdata-readers
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2F148-0137_ATBD_L1B_DDMCalibration_Rev2_Aug2018_release.pdf
5 https://search.earthdata.nasa.gov%2Fsearch%2Fgranules%3Fp%3DC2251464384-POCLOUD
5 https://podaac.jpl.nasa.gov%2FOPeNDAP-in-the-Cloud
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2Fatt_tables%2FAttitude_Table_FM_1.txt
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2Fatt_tables%2FAttitude_Table_FM_2.txt
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2Fatt_tables%2FAttitude_Table_FM_3.txt
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2Fatt_tables%2FAttitude_Table_FM_4.txt
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2Fatt_tables%2FAttitude_Table_FM_5.txt
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2Fatt_tables%2FAttitude_Table_FM_6.txt
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2Fatt_tables%2FAttitude_Table_FM_8.txt
5 https://doi.org%2F10.3998%2Fmpub.12741920
5 https://podaac.jpl.nasa.gov%2FPodaac%2Fthumbnails%2FCYGNSS_L1_V2.1.jpg
5 https://archive.podaac.earthdata.nasa.gov%2Fpodaac-ops-cumulus-docs%2Fcygnss%2Fopen%2FL1%2Fdocs%2Fatt_tables%2FAttitude_Table_FM_7.txt
5 https://podaac.jpl.nasa.gov%2FCitingPODAAC
5 https://cmr.earthdata.nasa.gov%2Fvirtual-directory%2Fcollections%2FC2251464384-POCLOUD
5 https://cygnss.engin.umich.edu/
5 https://podaac.jpl.nasa.gov/forum/viewtopic.php?f=16&t=1261
5 https://doi.org/10.1109/TGRS.2015.2502245
5 https://doi.org/10.1175/BAMS-D-18-0337.1
5 https://github.com/podaac/data-readers
5 https://cmr.earthdata.nasa.gov/virtual-directory/collections/C2251464384-POCLOUD
5 https://search.earthdata.nasa.gov/search/granules?p=C2251464384-POCLOUD
5 https://podaac.jpl.nasa.gov/OPeNDAP-in-the-Cloud
47 Attitude_Table_FM_1.txt https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_1.txt
47 Attitude_Table_FM_2.txt https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_2.txt
47 Attitude_Table_FM_3.txt https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_3.txt
47 Attitude_Table_FM_4.txt https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_4.txt
47 Attitude_Table_FM_5.txt https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_5.txt
47 Attitude_Table_FM_6.txt https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_6.txt
47 Attitude_Table_FM_7.txt https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_7.txt
47 Attitude_Table_FM_8.txt https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_8.txt
5 https://doi.org/10.3998/mpub.12741920
22 CYGNSS_L1_V2.1.jpg https://podaac.jpl.nasa.gov/Podaac/thumbnails/CYGNSS_L1_V2.1.jpg
5 https://podaac.jpl.nasa.gov/CitingPODAAC
33 CYGNSS_Handbook_April2016.pdf https://cygnss.engin.umich.edu/wp-content/uploads/sites/534/2021/06/CYGNSS_Handbook_April2016.pdf
5 148-0346-6_L1_v2.1_netCDF_Data_Dictionary.xlsx https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/148-0346-6_L1_v2.1_netCDF_Data_Dictionary.xlsx
33 148-0136_ATBD_L1A_DDMCalibration_Rev2_Aug2018_release.pdf https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/148-0136_ATBD_L1A_DDMCalibration_Rev2_Aug2018_release.pdf
5 https://journals.ametsoc.org/doi/10.1175/BAMS-D-14-00218.1
21 https://doi.org/10.1029/2019GL085134
33 148-0137_ATBD_L1B_DDMCalibration_Rev2_Aug2018_release.pdf https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/148-0137_ATBD_L1B_DDMCalibration_Rev2_Aug2018_release.pdf
5 https://docs.google.com/spreadsheets/d/1AFAZanVGDApLSnJQAAdPfOKoJQs0jnB8ZvIuD1Z5mAc/edit#gid=0
0 The metadata's original source. https://cmr.earthdata.nasa.gov/search/concepts/C2251464384-POCLOUD.iso19115

Tags

  • earth-science-platform-characteristics-spectral-engineering-flight-data-logs
  • earth-science-radar-spectral-engineering-radar-cross-section-bistatic-radar-cross-section
  • earth-science-radar-spectral-engineering-radar-reflectivity-zenith-signal-power
  • earth-science-radar-spectral-engineering-sigma-naught

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