S-NPP Product Descriptions: VNP09
Last update: November 1, 2016
Data Set Short Name:
Data Set Long Name:
NPP/VIIRS Atmospherically Corrected Surface Reflectance 6-Min L2 Swath 375m, 750m NRT
Suomi National Polar-orbiting Partnership (S-NPP)
Visible Infrared Imaging Radiometer Suite (VIIRS)
The VNP09_NRT is a Near Real Time (NRT) S-NPP/VIIRS 375 m, 750 m Atmospherically Corrected Surface Reflectance product. The NPP/VIIRS surface reflectance products are estimates of surface reflectance in each of the VIIRS reflective bands I1-I3, M1-M5, M7, M8, M10, and M11. The VNP09 Level-2 surface reflectance product contains approximately 6 minutes' worth of data. Surface reflectance for each moderate-resolution (750m) or imagery-resolution (375m) pixel is retrieved separately for the Level-2 products.
Surface reflectance is obtained by adjusting top-of-atmosphere reflectance to compensate for atmospheric effects. Corrections are made for the effects of molecular gases, including ozone and water vapor, and for the effects of atmospheric aerosols. The inputs to the surface reflectance algorithm include top-of-atmosphere reflectance for the VIIRS visible bands (VNP02MOD, VNP02IMG), the VIIRS cloud mask and aerosol product (NPP-CMIP_L2), aerosol optical thickness (NPP_VAOTIP_L2, NPP_VAMIP_L2), and atmospheric data obtained from a reanalysis (surface pressure, atmospheric precipitable water, and ozone concentration).
All surface reflectance products are produced for daytime conditions only. The product is produced under all atmospheric conditions except for night and oceans. Pixels when not produced are replaced by fill values in the Level-2 and Level-2G products.
file_naming_convention = "VNP09_NRT.AYYYYDDD.HHMM.VVV.YYYYDDDHHMMSS.hdf
- AYYYYDDD = Acquisition Year and Day of Year
- HHMM = Hour and minute of acquisition
- VVV = Version number
- YYYYDDDHHMMSS = Production Date and Time
- hdf = Hierarchical Data Format (version 4)
For more information read Suomi-NPP VIIRS Surface Reflectance User's Guide
or visit VIIRS Land website
~140 file per day
375m & 750m
File Size (MB):
NASA Suomi-NPP Land Science Team/MODIS Adaptive Processing System (MODAPS)