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Description

The WindSat Polarimetric Radiometer, launched on January 6, 2003 aboard the Department of Defense Coriolis satellite, was designed to measure the ocean surface wind vector from space. It developed by the Naval Research Laboratory (NRL) Remote Sensing Division and the Naval Center for Space Technology for the U.S. Navy and the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Integrated Program Office (IPO). In addition to wind speed and direction, the instrument can also measure sea surface temperature, soil moisture, ice and snow characteristics, water vapor, cloud liquid water, and rain rate. Unlike previous radiometers, the WindSat sensor takes observations during both the forward and aft looking scans. This makes the WindSat geometry of the earth view swath quite different and significantly more complicated to work with than the other passive microwave sensors. The Remote Sensing Systems (RSS, or REMSS) WindSat products are the only dataset available that uses both the fore and aft look directions. By using both directions, a wider swath and more complicated swath geometry is obtained. RSS providers of these SST data for the Group for High Resolution Sea Surface Temperature (GHRSST) Project, performs a detailed processing of WindSat instrument data in two stages. The first stage produces a near-real-time (NRT) product (identified by "rt" within the file name) which is made as available as soon as possible. This is generally within 3 hours of when the data are recorded. Although suitable for many timely uses the NRT products are not intended to be archive quality. "Final" data (currently identified by "v7.0.1a" within the file name) are processed when RSS receives the atmospheric mode NCEP FNL analysis. The NCEP wind directions are particularly useful for retrieving more accurate SSTs and wind speeds. The final "v7.0.1a" products will continue to accumulate new swaths (half orbits) until the maps are full, generally within 7 days. The version with letter "a" refers to the file incompliance with GHRSST format.

Product Summary

Platforms
CORIOLIS
Instruments
WINDSAT
Spatial Extent

N: 39.01 S: -39.06 E: 180 W: -179.99

Spatial Resolution
0.25 Decimal Degrees x 0.25 Decimal Degrees
Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2002-06-01 to 2020-10-19
Data Partner
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC) ,
Remote Sensing Systems (RSS)
Concept ID
C2036878925-POCLOUD
Data State
ACTIVE
Number of Files/Granules
6877
Processing Level
3
Published
Updated
Science Keywords
Sea Surface Temperature

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

Remote Sensing Systems. (2017). GHRSST Level 3U Global Subskin Sea Surface Temperature version7.0.1a from the WindSat Polarimetric Radiometer on the Coriolis satellite [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/GHWSA-3UR7A Date Accessed: 2026-04-21

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor Offset
cloud_liquid_water non L3U core field kg m-2 byte -128 -127 to 127 0.01 1.22
confidence_flag b0:1=within 50km rain, 0.6 dif mwoisst;b1:1=within 100km rain, 0.8 dif mwoisst;b2:1=within 150km ice, 0.6 dif mwoisst;b3:1=more than 5deg dif mwoisst;b4:1=3-sigma test;b5:1=(tmi only) within 150 km of land and 0.6 warmer than mwoisst;b6:1=diurnal estimate > 0.3 warming;b7:1=diurnal estimate > 1.0 warming N/A byte N/A N/A 1 N/A
cool_skin non L3U core field K byte -128 -127 to 127 0.01 -1
diurnal_amplitude non L3U core field K byte -128 -127 to 127 0.02 1
dt_analysis delta SST K byte -128 -127 to 127 0.1 N/A
l2p_flags These flags can help use the data N/A short N/A 0 to 2047 1 N/A
lat Latitude of retrievals degrees_north float -32768 -89.875 to 89.875 1 N/A
lon Longitude of retrievals degrees_east float -32768 -179.875 to 179.875 1 N/A
proximity_confidence 1=Bad, data rejected;2=Suspected Bad, data that has any confidence flags bit 0-5 thrown;3=Unprocessed proximity confidence flag, should be Good data;4=Good data N/A byte N/A N/A 1 N/A
quality_level This flag can help use the data N/A byte -128 0 to 5 1 N/A
rain_rate non L3U core field mm hr-1 byte -128 -127 to 127 0.1 12.7
rejection_flag b0:1=rain;b1:1=high wind/sunglint;b2:1=ice;b3:1=near land;b4:1=no data;b5:1=land; N/A byte N/A N/A 1 N/A
sea_ice_fraction ftp://eclipse.ncdc.noaa.gov/pub/OI-daily-v2/IEEE/YYYY/AVHRR/avhrr-only-v2.YYYYMMDD.gz 1 byte -128 -127 to 127 0.01 0.5
sea_surface_temperature Microwave SST = approximately the top 1 milimeter K short -32768 -5000 to 5000 0.01 273.15
sses_bias Sensor Specific Bias from in situ SSTs K byte -128 -127 to 127 0.01 N/A
sses_standard_deviation Sensor Specific STD from in situ SSTs K byte -128 -127 to 127 0.01 0.75
sst_dtime relative time of SST observations second int -32768 0 to 10000 10 N/A
time useful to help interpret sst_dtime seconds since 1981-01-01 00:00:00 int N/A N/A 1 N/A
water_vapor non L3U core field kg m-2 byte -128 -127 to 127 0.3 38.1
wind_speed non L3U core field; wind_speed_lf m s-1 byte -128 -127 to 127 0.2 25.4
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