STAR / SMCD / VIIRS Aerosol Calibration and Validation

The VIIRS aerosol processing produces three aerosol EDRs: AOT, APSP and SM.

• The VIIRS AOT and APSP EDRs are obtained by aggregating 8 x 8 0.75-km AOT and APSP IPs filtered by quality flags leading to EDR granules of 96 x 400 6-km EDR cells.
• The VIIRS SM EDR is also generated by filtering the IP results with quality flags and other criteria, but no aggregation is done, so the 0.75-km spatial resolution of the IP is retained.

The AOT and APSP EDRs are bundled in a single file. The name of this file starts with VAOOO. A VAOOO file contains the following for a single EDR granule:

• AOT at 550 nm,
• AOTs at ten M bands (412, 445, 488, 555, 672, 746, 865, 1240, 1610, and 2250 nm),
• Angstrom exponent,
• fine mode fraction (in percentage) over ocean,
• AOT and Angstrom exponent factors (slope and offset) used to unscale the AOT and Angstrom exponent from their scaled integer values,
• quality flags (QF1-QF5).

The SM product is recorded in a file whose name starts with VSUMO. The VSUMO file contains the following for a single EDR granule:

• suspended matter type (dust, smoke, sea salt, volcanic ash),
• smoke concentration,
• smoke concentration factors, used to unscale the smoke concentration from its scaled integer value,
• quality flags (QF1-QF3).

Detailed description of the contents of the above files are provided in the Common Data Format Control Book (CDFCB) linked from the Documentation page.

The VAOOO and VSUMO files can be accessed from NOAA CLASS.

To order the VAOOO and VSUMO files from CLASS:

1. select JPSS Visible Infrared Imaging Radiometer Suite Environmental Data Record (VIIRS_EDR) from the drop-down list at the top of the CLASS page;
2. click GO;
3. on the resulting page select VIIRS Aerosol Optical Thickness (AOT) EDR (VAOOO) and/or VIIRS Suspended Matter EDR (VSUMO) from the Environmental Data Record section under Advanced Search.
4. To obtain the corresponding geo-location files
• select, on the same page, VIIRS Aerosol (aggregated) EDR Ellipsoid Geolocation (GAERO) to go with the AOT and APSP data.
• For getting the geo-location file GMTCO to go with the SM data see the Intermediate Products page.