The ACSPO VIIRS L3U (Level 3 Uncollated) product is a gridded version of the ACSPO VIIRS L2P product available here http://podaac.jpl.nasa.gov/dataset/VIIRS_NPP-OSPO-L2P-v2.41
. Data files are 10 min granules in netcdf4 format compliant with the GHRSST Data Specification version 2 (GDS2). There are 144 granules per 24hr interval, with a total data volume of 1GB/day. Fill values are reported at all ... invalid pixels, including pixels at >5 km inland. For each valid water pixel (defined as ocean, sea, lake or river, and up to 5 km inland), the following layers are reported: SSTs, ACSPO clear-sky mask (ACSM; provided in each grid as part of l2p_flags, which also includes day/night, land, ice, twilight, and glint flags), NCEP wind speed, and ACSPO SST minus reference (Canadian Met Centre 0.2deg L4 SST; available at http://podaac.jpl.nasa.gov/dataset/CMC0.2deg-CMC-L4-GLOB-v2.0). Only L2P SSTs with QL=5 were gridded, so all valid SSTs are recommended for the users. Per GDS2 specifications, two additional Sensor-Specific Error Statistics layers (SSES bias and standard deviation) are reported in each pixel with valid SST. The ACSPO VIIRS L3U product is monitored and validated against in situ data (Xu and Ignatov, 2014) in SQUAM (Dash et al, 2010).