Version 2 (V2) SMAP Sea Surface Salinity (SSS) data are available from Remote Sensing Systems (RSS) at spatial resolutions of 40km and 70km.
As is the case for the 40-km resolution product, the 70-km product is resampled onto a 0.25° fixed Earth grid using a Backus-Gilbert type optimum interpolation (OI). In the case of the 70-km product, the target cell of the OI is a circular footprint with a diameter of 70 km. Compared to the 40-km product, the 70-km is spatially smoother and the random noise is reduced by 60%. For most oceanographic applications, it is recommended that the new 70-km product be used.
Data sets comprising the latest release include the Level 2C orbital data and two Level 3 (L3) mapped salinity products: an 8-day running mean product based on the repeat orbit of the SMAP mission, along with a monthly average product. All products are in the netCDF4 file format, and the L3 products are CF/ACDD metadata standards compliant. The formats of the 40km and 70 km products are the same.
The SMAP-SSS V2 70km data sets are described and discoverable via the PO.DAAC data portal. The RSS SMAP Salinity: Version 2 Validated Release document (release notes, SMAP ATBD (Algorithm Theoreotical Basis Document), validation analysis, and file specification document is available here. The data are also accessible via a range of PO.DAAC tools and services: OPeNDAP, THREDDS, PODAAC-WS and LAS.
General information regarding the SMAP mission is available from the mission website and also via PO.DAAC's SMAP and salinity webpages.View V3 SMAP Maps