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Description

This dataset contains the Version 3.0 CYGNSS Level 3 Science Data Record which provides the average wind speed and mean square slope (MSS) on a 0.2x0.2 degree latitude by longitude equirectangular grid obtained from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. The Level 2 Delay Doppler Map (DDM) data are used in the direct processing of the average wind speed and MSS data that are binned on the Level 3 grid. 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. A single netCDF-4 data file is produced for each day of operation with an approximate 6 day latency. This version supersedes Version 2.1; https://doi.org/10.5067/CYGNS-L3X21. The reported sample locations are determined by the specular points corresponding to the Delay Doppler Maps (DDMs). The Version 3.0 release inherits all improvements made to the version 3.0 Level 2 data intended to improve the quality of the wind speed retrievals. For a full list of improvements to the version 3.0 Level 2 data, please refer to: https://doi.org/10.5067/CYGNS-L2X30.

Product Summary

Platforms
CYGNSS
Instruments
DDMI
Spatial Extent

N: 40 S: -40 E: 180 W: -180

Spatial Resolution
0.2 Decimal Degrees x 0.2 Decimal Degrees
Geographic Region
GLOBAL ,
TROPICS
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2018-08-01 to Present
Data Partner
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC) ,
Cyclone Global Navigation Satellite System Mission, NASA Earth Science System Pathfinder, University of Michigan (NASA/ESSP/UMICH/CYGNSS)
Concept ID
C2251464874-POCLOUD
Data State
ACTIVE
Number of Files/Granules
1467
Processing Level
3
Published
Updated
Science Keywords
Surface Winds ,
Surface Winds

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

CYGNSS. (2020). CYGNSS Level 3 Science Data Record Version 3.0 [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/CYGNS-L3X30 Date Accessed: 2025-12-14

Documents

USER'S GUIDE

ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)

ANOMALIES

GENERAL DOCUMENTATION

PUBLICATIONS

DATA CITATION GUIDELINES

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
epoch_time Timestamp coordinate is at the center of the 1 hr bin, at 1 hour resolution referenced by the historical Epoch reference date/time. The Epoch reference date/time corresponds to the first observation time window in the CYGNSS data record after the automatic gain control was turned off. Total number of timestamps in a file corresponds to one UTC day. This value is rounded to the nearest hour since leap seconds may have occurred making the number of hours since the start of the mission not exact. hours since 2018-08-01 00:30:00.000000000 int N/A N/A 1
lat Latitude coordinate at the center of the 0.2 degree bin, degrees_north, at 0.2 degree resolution. Range is -39.9 .. 39.9. degrees_north float N/A N/A 1
lon Longitude coordinate at the center of the 0.2 degree bin, degrees_east, at 0.2 degree resolution. Range is 0.1 .. 359.9. degrees_east float N/A N/A 1
mean_square_slope Mean MSS in the bin over the spatial and temporal intervals specified by the bin's boundaries. 1 float -9999 N/A 1
mean_square_slope_uncertainty Standard deviation of the error in the mean of all L2 samples of the MSS within the bin. 1 float -9999 N/A 1
num_mss_samples The number of L2 MSS samples used to calculate mean_square_slope. 1 int -99 N/A 1
num_wind_speed_samples The number of L2 wind speed samples used to calculate wind_speed. 1 int -99 N/A 1
num_yslf_wind_speed_samples The number of L2 young sea limited fetch wind speed samples used to calculate wind_speed. 1 int -99 N/A 1
time Timestamp coordinate at the center of the 1 hr bin, at 1 hour resolution. Range is one UTC day. hours since 2018-08-02 00:30:00.000000000 byte N/A N/A 1
wind_speed Minimum variance estimate of the mean wind speed in the bin over the spatial and temporal intervals specified by the bin's boundaries. This is done using an inverse-variance weighted average of all L2 samples of the wind speed that were made within the bin. m s-1 float -9999 N/A 1
wind_speed_uncertainty Standard deviation of the error in the mean of all L2 samples of the wind speed within the bin. m s-1 float -9999 N/A 1
yslf_wind_speed Minimum variance estimate of the young sea limited fetch mean wind speed in the bin over the spatial and temporal intervals specified by the bin's boundaries. This is done using an inverse-variance weighted average of all L2 samples of the wind speed that were made within the bin. m s-1 float -9999 N/A 1
yslf_wind_speed_uncertainty Standard deviation of the error in the mean of all L2 samples of the young sea limited fetch wind speed within the bin. m s-1 float -9999 N/A 1
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