RSS SMAP Level 3 Sea Surface Salinity Standard Mapped Image 8-Day Running Mean V4.0 Validated Dataset
2 Publications Cited this Dataset >>
Citation metrics available for years (2015-2019)
Please contact us if there are any discrepancies or inaccuracies found below.
DescriptionThe version 4.0 SMAP-SSS level 3, 8-Day running mean gridded product is based on the fourth release of the validated standard mapped sea surface salinity (SSS) data from the NASA Soil Moisture Active Passive (SMAP) observatory, produced operationally by Remote Sensing Systems (RSS). Enhancements with this release include: use of an improved 0.125 degree land correction table with land emission based on SMAP TB; replacement of the previous NCEP sea-ice mask with one based on RSS AMSR-2 and implementing a sea-ice threshold of 0.3% (gain weighted sea-ice fraction); revised solar flagging that depends on glint angle and wind speed; inclusion of estimated SSS-uncertainty; consolidation of both 40KM and 70KM SMAP-SSS datasets as variable fields in a single data product. Daily data files for this product are based on SSS averages spanning an 8-day moving time window. SMAP data begins on April 1,2015 and is ongoing. L3 products are global in extent and gridded at 0.25degree x 0.25degree with a default spatial feature resolution of approximately 70KM. Note that while a SSS 40KM variable is also included in the product, for most open ocean applications, the default SSS variable (70KM) is best used as they are significantly less noisy than the 40KM data. 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, primarily from WindSat, for the surface roughness correction required for the surface salinity retrieval.
Dataset TypeOPEN
Processing Level3
CoverageRegion: Global
Northernmost Latitude: 90 degrees
Southernmost Latitude: -90 degrees
Westernmost Longitude: -180 degrees
Easternmost Longitude: 180 degrees
Time Span: 2015-Mar-27 to Present
Granule Time Span: 2015-Mar-27 to 2020-Sep-23
ResolutionSpatial Resolution: 0.25 degrees (Latitude) x 0.25 degrees (Longitude)
Temporal Resolution: 8 Day
ProjectionType: Gridded
Ellipsoid: WGS 84
Latency72 hours
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
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: Remote Sensing Systems (RSS)
Release Place: Remote Sensing Systems, 444 Tenth Street, Suite 200, Santa Rosa, CA 95401, USA
Release Date: 2019-Aug-28
Keyword(s)RssSmapSSSv4, V4, L3, Level 3, 8 day running mean, SMAP, SMAP-SSS, Soil Moisture Active, Passive, salinity, polar, sun-synchronous, sss, sea surface, salinity, psu, NASA, project, mission, RSS, REMSS, Remote Sensing Systems
Questions related to this dataset? Contact
User's Guide
User's Guide
SMAP-SSS V4.0 Technical Guide (ATBD, Validation Analysis, Product Format Specification)
Project Materials
SMAP-SSS v4.0 Documentation Package
ATBD, Validation Analysis, Product Specifications, etc
Additional Sites
SMAP Mission Website
NASA SMAP Mission Website
SMAP-SSS on RSS Website
Remote Sensing Systems SMAP Sea Surface Salinity Website
PO.DAAC SMAP-SSS Mission page
SMAP-SSS Project and Instrument Overview
Known Issues
Known issues README
Know issues README
Missing Ancillary L2 File Listing
Dynamically updated RSS webpage listing L2 files with missing ancillary inputs
Bad Orbit L2 File Listing
Dynamically updated RSS webpage listing L2 files with Bad Orbits
Known Issues
Information on Data Outages & Known Issues
Citation Remote Sensing Systems (RSS). 2019. RSS SMAP Level 3 Sea Surface Salinity Standard Mapped Image 8-Day Running Mean V4.0 Validated Dataset. Ver. 4.0. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at

Download Citation

For more information see Data Citations and Acknowledgments.

Journal Reference Meissner, T. and F. J. Wentz, 2019: Remote Sensing Sytems SMAP Ocean Surface Salinities, Version 4.0 validated release. Remote Sensing Systems, Santa Rosa, CA, USA.