NOAA CoastWatch co-gridded VIIRS SST from ACSPO

NOAA CoastWatch creates these co-gridded AVHRR SST Level 3 daily composites to be compatible in format and projection with the VIIRS Ocean Color Level 3 daily composites (Note VIIRS sector full resolution is 750m).  The input for these CoastWatch Sector SST files is daily, near real time ACSPO SST for AVHRR. 

These SST products are intended for users who seek AVHRR ACSPO SST data co-registered with CoastWatch ocean color data from AVHRR and are not the NOAA operational L3U ACSPO products. The CoastWatch co-gridded products are available in regional Sectors at full 1.2 kilometer AVHRR resolution and as global products at 4 km resolution.  The regional products consist of 24 sectors (see Sector map below) mapped to the VIIRS ocean color sectors, and polar stereographic regions NP06 and SP06 mapped identically to the CoastWatch VIIRS ice products.  The 4 km global product is also mapped identically to the corresponding CoastWatch VIIRS ocean color product.

These products start with the operational ACSPO L2P product (in the canonical ten-minute granule form), ingest that for CoastWatch processing, and then georegister and mask those granule-level products.  The mask applied is 0xC002.That rejects pixels flagged 0x40, 0x80, and 0xC0 (anything but confident clear) and pixels flagged 0x02 (land).  The L3 masked granule products are aggregated to a daily product on the same grid on the basis of the last pixel seen.  The 4 km global product is created by averaging the non-null values for the pixels of the daily sector maps in a 5x5 grid.

Note: CoastWatch also distributes a gap-filled polar plus geosynchronous blended daily SST analysis product suite at 5 km resolution.