CYGNSS Level 1 Science Data Record Version 3.2

Description

This CYGNSS Level 1 (L1) science data record dataset contains the version 3.2 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 3.1: https://doi.org/10.5067/CYGNS-L1X31. 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 correction for coarse quantization effects that was implemented in v3.1 for the signal portion of the DDM has been updated to include a correction to the noise floor portion of the DDM. This update is found to improve the sensitivity to soil moisture over land and to have a minimal effect on the sensitivity to wind speed over ocean. An update is made to the correction for the temperature dependence of the receiver electronics. This update reduces slow variations in calibration bias associated with a ~60 day oscillation in the mean temperature of the satellites. L1 variables over land and ocean are now combined in common netcdf data files, with additional details added regarding the specular point calculation over land. Nadir (science) antenna pattern and NBRCS rescaling has been updated to improve the inter-satellite consistency of the L1 calibration.

The CYGNSS is a NASA Earth System Science Pathfinder Mission that is intended to collect the first frequent space‐based measurements of surface wind speeds in the inner core of tropical cyclones. Made up of a constellation of eight micro-satellites, the observatories provide nearly gap-free Earth coverage using an orbital inclination of approximately 35° from the equator, with a mean (i.e., average) revisit time of seven hours and a median revisit time of three hours. This inclination allows CYGNSS to measure ocean surface winds between approximately 38° N and 38° S latitude. This range includes the critical latitude band for tropical cyclone formation and movement.

Resources

Name Format Description Link
21 Forum Post Capturing Changes to CYGNSS Sampling Rate https://podaac.jpl.nasa.gov/forum/viewtopic.php?f=16&t=1261
22 Thumbnail https://podaac.jpl.nasa.gov/Podaac/thumbnails/CYGNSS_L1_V3.2.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=C2832195379-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 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_4.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 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 CYGNSS Handbook https://doi.org/10.3998/mpub.12741920
21 CYGNSS Mission Page at University of Michigan https://cygnss.engin.umich.edu/
21 Search results for publications that cite this dataset by its DOI. https://scholar.google.com/scholar?q=10.5067%2FCYGNS-L1X32
33 Deriving Surface Winds from Tropical Cyclones https://cygnss.engin.umich.edu/wp-content/uploads/sites/534/2021/06/CYGNSS_Handbook_April2016.pdf
21 Google Sheet Log of Anomalous CYGNSS Sampling Events https://docs.google.com/spreadsheets/d/1AFAZanVGDApLSnJQAAdPfOKoJQs0jnB8ZvIuD1Z5mAc/edit#gid=0
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 Generic Data Readers https://github.com/podaac/data-readers
21 CYGNSS L1 V3.2 netCDF Data Dictionary https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/148-0346-10_Level_1_netCDF_Data_Dictionary.xlsx
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
21 Forum Post Capturing Changes to CYGNSS Sampling Rate https://forum.earthdata.nasa.gov/viewtopic.php?t=5657
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 HTTPS endpoint for data browse and download https://cmr.earthdata.nasa.gov/virtual-directory/collections/C2832195379-POCLOUD
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 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
33 Level 1B DDM Calibration Algorithm Theoretical Basis Document, S. Gleason, CYGNSS Project Document 148-0137, Rev 6, 8 December 2023. https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/148-0137_L1B_DDM_Calibration_ATBD_R6.pdf
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 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
33 Level 1A DDM Calibration Algorithm Theoretical Basis Document, S. Gleason, CYGNSS Project Document 148-0136, Rev 4, 8 December 2023. https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/148-0136_L1A_DDM_Calibration_ATBD_R4.pdf

Tags

  • spectral-engineering
  • radar
  • earth-science

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