CYGNSS Level 1 Science Data Record Version 3.1

Description

This Level 1 (L1) dataset contains the Version 3.1 geo-located Delay Doppler Maps (DDMs) calibrated into Power Received (Watts) and Bistatic Radar Cross Section (BRCS) expressed in units of m2 from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. This version supersedes Version 3.0; https://doi.org/10.5067/CYGNS-L1X30. 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. Here is a summary of improvements the calibration and processing changes to the Version 3.1 data: The CYGNSS science antenna gain patterns have been adjusted to improve the accuracy of the ocean surface scattering cross section (a.k.a. the NBRCS) calibration. They are adjusted so that the annual average observed NBRCS matches the model-predicted average as derived from Wavewatch-3 estimates of the surface roughness with the appropriate spectral tail extension added to the roughness spectrum. The adjustment is made independently at each position in the science antenna pattern. A correction for coarse quantization effects by the on-board digital processor has also been added. This reduces the effects of radio frequency interference, which appeared as calibration biases in the v3.0 L1 NBRCS and retrieval biases in the v3.0 L2 wind speed that were persistent at certain locations.

Resources

Name Format Description Link
21 Google Sheet Log of Anomalous CYGNSS Sampling Events https://docs.google.com/spreadsheets/d/1AFAZanVGDApLSnJQAAdPfOKoJQs0jnB8ZvIuD1Z5mAc/edit#gid=0
33 Deriving Surface Winds from Tropical Cyclones https://cygnss.engin.umich.edu/wp-content/uploads/sites/534/2021/06/CYGNSS_Handbook_April2016.pdf
21 Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_2.txt
21 Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_3.txt
21 Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_5.txt
21 Search results for publications that cite this dataset by its DOI. https://scholar.google.com/scholar?q=10.5067%2FCYGNS-L1X31
21 Forum Post Capturing Changes to CYGNSS Sampling Rate https://podaac.jpl.nasa.gov/forum/viewtopic.php?f=16&t=1261
21 A CYGNSS-based algorithm for the detection of inland waterbodies https://doi.org/10.1029/2019GL085134
21 Data Use and Citation Policy https://podaac.jpl.nasa.gov/CitingPODAAC
22 Thumbnail https://podaac.jpl.nasa.gov/Podaac/thumbnails/CYGNSS_L1_V3.1.jpg
21 Pascual, D., M. P. Clarizia, C. S. Ruf (2021). Improved CYGNSS Wind Speed Retrieval Using Significant Wave Height Correction. Remote Sensing, doi: 10.3390/rs13214313. https://doi.org/10.3390/rs13214313
21 Browse granule search results in Earthdata Search https://search.earthdata.nasa.gov/search/granules?p=C2146321631-POCLOUD
21 Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_1.txt
21 CYGNSS Handbook https://doi.org/10.3998/mpub.12741920
21 Gleason, S., C. Ruf, M. P. Clarizia, A. O'Brien, 'Calibration and Unwrapping of the Normalized Scattering Cross Section for the Cyclone Global Navigation Satellite System (CYGNSS)', IEEE Trans. Geosci. Remote Sens., doi:10.1109/TGRS.2015.2502245, 2016. https://doi.org/10.1109/TGRS.2015.2502245
21 CYGNSS Mission Page at University of Michigan https://cygnss.engin.umich.edu/
21 Generic Data Readers https://github.com/podaac/data-readers
21 CYGNSS L1 V3.1 netCDF Data Dictionary https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/148-0346-9_Level_1_netCDF_Data_Dictionary.xlsx
21 Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_6.txt
21 Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_7.txt
21 Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_8.txt
21 Wang, T., Ruf, C. S., Gleason, S., O'Brien, A. J., McKague, D. S., Block, B. P., Russel, A. 2021. Dynamic Calibration of GPS Effective Isotropic Radiated Power for GNSS-Reflectometry Earth Remote Sensing, IEEE Trans. Geosci. Remote Sens. 10.1109/TGRS.2021.3070238. https://doi.org/10.1109/TGRS.2021.3070238
21 Gleason, S., M. M. Al-Khaldi, C. Ruf, D. S. McKague, T. Wang, A. Russel (2021). Characterizing and Mitigating Digital Sampling Effects on the CYGNSS Level 1 Calibration. IEEE Trans. Geosci. Remote Sens., doi: 10.1109/TGRS.2021.3120026. https://doi.org/10.1109/TGRS.2021.3120026
33 Level 1A DDM Calibration Algorithm Theoretical Basis Document, S. Gleason, CYGNSS Project Document 148-0136, Rev 2, 20 Aug. 2018. https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/148-0136_ATBD_L1A_DDMCalibration_Rev2_Aug2018_release.pdf
33 Level 1B DDM Calibration Algorithm Theoretical Basis Document, S. Gleason, CYGNSS Project Document 148-0137, Rev 4, 09 Nov. 2021. https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/148-0137_ATBD_L1B_DDM_Calibration_R4.pdf
21 Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_4.txt
21 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. https://journals.ametsoc.org/doi/10.1175/BAMS-D-14-00218.1
21 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/10.1175/BAMS-D-18-0337.1
21 HTTPS endpoint for data browse and download https://cmr.earthdata.nasa.gov/virtual-directory/collections/C2146321631-POCLOUD

Tags

  • spectral-engineering
  • radar
  • earth-science

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