VIIRS AOD
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The VIIRS aerosol algorithm over land retrieves AOD and surface reflectance simultaneously by selecting the aerosol model, AOD, and surface reflectance that give the minimum residual between derived and empirically prescribed spectral surface reflectance ratios. The VIIRS over ocean algorithm retrieves AOD by selecting the aerosol model and AOD value that give the minimum residual between derived and observed top of the atmosphere reflectances at multiple visible bands. Surface reflectance over ocean is calculated analytically using wind speed as input.
Example image
http://www.star.nesdis.noaa.gov/smcd/viirs_aerosol/WEB/html/nesdis.viirs.web.html
| Satellite | Suomi National Polar Partnership (NASA-NOAA) |
| Instrument(s) | Visible/Infrared Imaging Radiometer Suite (VIIRS) |
| Contact details | Shobha.Kondragunta[at]noaa.gov, Istvan.Laszlo[at]noaa.gov |
| Parameter(s) | Aerosol Optical Depth at 550 nm |
| Aerosol algorithm | VIIRS Aerosol Optical Thickness (AOT) and Particle Size Parameter (APSP) Algorithm |
| Cloud screening |
VIIRS Cloud Mask (VCM) |
| Aerosol model | land: dust, high absorbing smoke, low absorbing smoke, clean urban, polluted urban aerosols; ocean: mixture of fine mode and coarse mode particles |
| Retrieval assumptions | aerosol microphysical properties; Lambertian surface over land |
| Retrieval limitations |
Not available over bright surfaces and inland water bodies. Snow contamination in retrieved AOT over high latitude; measurement range is 0 to 2; no negative values and AOT greater than 2.0 are reported |
| Spatial, temporal coverage |
Land: January 23, 2013 to present (validated); Ocean: May 2, 2012 to present (validated) NRT data (imagery) from Direct Broadcast March 1, 2013 to present with coverage over CONUS and Alaska Data production error (not recommended): October 15 to November 27, 2012 |
| Spatial, temporal resolution | 750 m or 6km / 3000 km swath / daily, 0.25o x 0.25o gridded daily |
| Operations status | Operational |
| Validation status | validated |
| Quality control | extensive internal tests; product comes with high, medium, low quality flags; recommend using AOT with a “high” quality flag; only high quality AOT EDR data are used in generating the gridded product |
| last algorithm version | Mx8.8 |
| last validation | 3/2015 |
| Algorithm description | Product format description |
| Version explanation | Validation summary |
| Publications |
| Product data access |
| Image / quicklook data access |