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Imaging · collection · 2018

CYGNSS Level 2 Science Data Record Version 2.1

Listed in NASA Earthdata CMR and NASA Data Portal — shown once because both records carry DOI 10.5067/cygns-l2x21

This dataset contains the Version 2.1 CYGNSS Level 2 Science Data Record which provides the time-tagged and geolocated average wind speed (m/s) and mean square slope (MSS) with 25x25 kilometer resolution from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation.

Description

This version supersedes Version 2.0. The reported sample locations are determined by the specular points corresponding to the Delay Doppler Maps (DDMs).

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. Only one netCDF data file is produced each day (each file containing data from up to 8 unique CYGNSS spacecraft) with a latency of approximately 6 days (or better) from the last recorded measurement time. The Version 2.1 release represents the second science-quality release.

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Here is a summary of improvements that reflect the quality of the Version 2.1 data release: 1) revised Geophysical Model Functions (GMFs) for both Fully Developed Seas (FDS) and Young Seas with Limited Fetch conditions, to be consistent with the calibration changes made to the v2.1 Level 1 science data products.; 2) Revised covariance matrix between DDMA and LES versions of the FDS wind speed retrieval, used by the minimum variance estimator, resulting from changes made to the v2.1 Level 1 science data products; 3) Revised debiasing algorithm coefficients used by the FDS L2 retrieval algorithm, resulting from changes made to the v2.1 Level 2 science data products; 4) revised quality control (Q/C) flags related to the required level of consistency between DDMA and LES versions of the FDS wind speed retrieval (the errors in the two retrievals are now less correlated so larger discrepancies are allowed; if either retrieval is not available, the sample receives a fatal Q/C flag); 5) new Q/C flag related to the block type of the GPS satellite which provided the transmitted signal.

Samples using block II-F signals receive a fatal Q/C flag due to the higher level of uncertainty in their radiated power; 6) revised wind speed uncertainty values as a function of RCG and wind speed, plus a new dependence of the uncertainty on GPS block type to reflect the higher uncertainty in GPS radiated power for block II-F satellites.

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Catalogue records · 3

Topics

Stated by source
Bistatic Radar Cross-Section · Cyclone Global Navigation Satellite System · Delay Doppler Mapping Instrument · Ocean Surface Wind Speed · Sigma Naught · Surface Winds
From keywords
Astronomy & Astrophysics · Earth & Environmental Science · Engineering · Ocean & Atmospheric Science · Physics
Provenance · 2 source records, 21 field assertions
SourceKeyLast seenRaw
NASA Earthdata CMRC2251464495-POCLOUD15 d agoJSON v1
NASA Data Portal22880d05-8c13-4ed3-adfb-11de36e007fb12 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[field].local:field:astronomymapping · data nasa govconnector:data_nasa_gov@1.0.0
concepts[field].local:field:earth-environmentalmapping · data nasa govconnector:data_nasa_gov@1.0.0
concepts[field].local:field:engineeringmapping · data nasa govconnector:data_nasa_gov@1.0.0
concepts[field].local:field:ocean-atmosphericmapping · data nasa govconnector:data_nasa_gov@1.0.0
concepts[field].local:field:physicsmapping · data nasa govconnector:data_nasa_gov@1.0.0
concepts[instrument].gcmd_instrument:ddmisource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[measured_variable].gcmd:earth-science/oceans/ocean-winds/surface-windssource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[measured_variable].gcmd:earth-science/oceans/ocean-winds/surface-winds/ocean-surface-wind-speedsource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[measured_variable].gcmd:earth-science/spectral-engineering/radar/radar-cross-section/bistatic-radar-cross-sectionsource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[measured_variable].gcmd:earth-science/spectral-engineering/radar/sigma-naughtsource · NASA CMRconnector:nasa_cmr@1.0.0
concepts[platform].gcmd_platform:cygnsssource · NASA CMRconnector:nasa_cmr@1.0.0
created_datesource · NASA CMRconnector:nasa_cmr@1.0.0
descriptionsource · NASA CMRconnector:nasa_cmr@1.0.0/umm/Abstract
license_textsource · data nasa govconnector:data_nasa_gov@1.0.0
publication_datesource · NASA CMRconnector:nasa_cmr@1.0.0
spatialsource · NASA CMRconnector:nasa_cmr@1.0.0/umm/SpatialExtent
temporalsource · NASA CMRconnector:nasa_cmr@1.0.0/umm/TemporalExtents
titlesource · NASA CMRconnector:nasa_cmr@1.0.0/umm/EntryTitle
updated_datesource · NASA CMRconnector:nasa_cmr@1.0.0
version_labelsource · NASA CMRconnector:nasa_cmr@1.0.0