JPL SMAP Level 2B Near Real-time CAP Sea Surface Salinity V4.2 Validated Dataset

JPL SMAP Level 2B Near Real-time CAP Sea Surface Salinity V4.2 Validated Dataset
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DOI10.5067/SMP42-2NOCS
Short NameSMAP_JPL_L2B_NRT_SSS_CAP_V42
DescriptionThis is the PI-produced JPL SMAP-SSS V4.2, level 2B NRT CAP, validated sea surface salinity (SSS) and extreme winds orbital/swath product from the NASA Soil Moisture Active Passive (SMAP) observatory available in near real-time with a latency of about 6 hours. It is based on the Combined Active-Passive (CAP) retrieval algorithm developed at JPL originally in the context of Aquarius/SAC-D and now extended to SMAP. SMAP-SSS V4.2 is a complete reprocessing of the entire mission series following on from the reprocessing of the source L1B-TB data by the SMAP mission on 6/4/2018. Updates in v4.2 include: improvement in the brightness temperature (TB) calibration using an adjusted reflector emissivity, inclusion of a Sea Surface Temperature (SST) dependent flat surface emissivity model, use of updated land correction tables, and inclusion of averaged ice concentration ancillary data in the v4.2 product. The JPL SMAP-SSS L2B CAP NRT product includes data for a range of parameters: derived SMAP sea surface salinity, SSS uncertainty and wind speed/direction data for extreme winds, brightness temperatures for each radiometer polarization, ancillary reference surface salinity, ice concentration, wind and wave height data, quality flags, and navigation data. Each data file covers one 98-minute orbit (15 files per day). Data begins on April 1,2015 and is ongoing, with a 3 day latency in processing and availability. Observations are global in extent and provided at 25km swath grid with an approximate spatial resolution of 60 km. The SMAP satellite is in a near-polar orbit at an inclination of 98 degrees and an altitude of 685 km. It has an ascending node time of 6 pm and is sun-synchronous. With its 1000km swath, SMAP achieves global coverage in approximately 3 days, but has an exact orbit repeat cycle of 8 days. On board Instruments include a highly sensitive L-band radiometer operating at 1.41GHz and an L-band 1.26GHz radar sensor providing complementary active and passive sensing capabilities. Malfunction of the SMAP scatterometer on 7 July, 2015, has necessitated the use of collocated wind speed for the surface roughness correction required for the surface salinity retrieval.
Version4.2
Dataset TypeOPEN
MeasurementOceans > Ocean Winds > Surface Winds
Oceans > Salinity/Density > Salinity > Salinity
Processing Level2B
CoverageRegion: Global
Northernmost Latitude: 90 degrees
Southernmost Latitude: -90 degrees
Westernmost Longitude: -180 degrees
Easternmost Longitude: 180 degrees
Time Span: 2015-Apr-01 to Present
ResolutionSpatial Resolution: 25 km (Along) x 25 km (Across)
ProjectionType: Swath
Detail:
Ellipsoid: Circular near-polar
Latency5 hours
Swath Width1 m
Sample Frequency-
Temporal Repeat (Nominal)8 Day
Temporal Repeat (Min)8 Day
Temporal Repeat (Max)8 Day
Platform/Sensor
SMAP
Platform
Name: NASA Soil Moisture Active Passive (SMAP) (SMAP)
Orbit Period: 98.5 minutes
Inclination Angle: 98 degrees
Ascending Node: 1970-Jan-01 00:00:00
/
SMAP L-BAND RADIOMETER
SENSOR
Name: SMAP L-Band Radiometer (SMAP L-BAND RADIOMETER)
Swath Width: 1000 km
Description: L-Band 1.41 GHz Radiometer aboard the NASA SMAP (Soil Moisture Active Passive) satellite observatory

ProjectSoil Moisture Active Passive (SMAP) Sea Surface Salinity (SSS) (SMAP-SSS)
Data ProviderCreator: JPL Climate Oceans and Solid Earth group
Release Place: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA91109, USA
Release Date: 2019-Jan-24
Resource: http://podaac.jpl.nasa.gov/smap
Keyword(s)JPLSMAPSSSV42, SMAP, SMAP-SSS, Soil Moisture Active Passive, salinity, polar, sun-synchronous, sss, psu, NASA, project, mission, JPL, CAP, combined active/passive, L2B
Persistent IDPODAAC-SMP42-2NOCS
Questions related to this dataset? Contact podaac@podaac.jpl.nasa.gov
User's Guide
User's Guidehttps://podaac-tools.jpl.nasa.gov/drive/files/allData/smap/docs/JPL-CAP_V42/SMAP-SSS_JPL_V4.2_Documentation.pdf
JPL CAP SMAP-SSS V4.2 Technical Guide (ATBD, Validation Analysis, Product Format Specification)
Project Materials
JPL CAP SMAP-SSS v4.2 Documentation Packagehttps://podaac-tools.jpl.nasa.gov/drive/files/allData/smap/docs/JPL-CAP_V42/
ATBD, Validation Analysis, Product Specifications, etc
Additional Sites
PO.DAAC SMAP-SSS Mission pagehttp://podaac.jpl.nasa.gov/smap
SMAP-SSS Project and Instrument Overview
NASA SMAP Mission Websitehttp://smap.jpl.nasa.gov/
NASA SMAP Mission Website
Citation JPL Climate Oceans and Solid Earth group. 2019. JPL SMAP Level 2B Near Real-time CAP Sea Surface Salinity V4.2 Validated Dataset. Ver. 4.2. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at http://dx.doi.org/10.5067/SMP42-2NOCS.

For more information see Data Citations and Acknowledgments.

Journal Reference Fore,A.G, S.H. Yueh, W. Tang, B.W. Stiles, and A.K. Hayashi (2016). Combined Active/Passive Retrievals of Ocean Vector Wind and Sea Surface Salinity With SMAP. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 54, NO. 12. p.7396-7404. DOI: 10.1109/TGRS.2016.2601486