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NPP VIIRS and AQUA MODIS Intercomparison

VIIRS is undergoing extensive on-orbit calibration and validation to keep radiometric accuracy well within specification and ensure that the data quality meet the stringent requirements of weather and climate quality calibration. VIIRS radiometric accuracy and stability has been continuously monitored since early launch by estimating radiometric bias of VIIRS relative to MODIS. Different techniques have been used to compare VIIRS measurements with AQUA MODIS. The techniques used for VIIRS and MODIS intercomaprison are shown below along with the results:


a. Extended Simultaneous Nadir Overpass (SNO-x) (Note: Results will be updated biweekly.)

image: Image acquired by VIIRS

Figure: VIIRS Radiometric Bias before (left) and after (right)
correcting the impact of spectral differences in VIIRS and MODIS RSR



b . Simultaneous Nadir Overpass (SNO) (Note: Results will be updated biweekly.)

image: Image acquired by VIIRS

Figure: VIIRS Radiometric Bias ((VIIRS-MODIS)100%)/MODIS.
The figure also shows the VIIRS and MODIS matching bands.


c. Methodology (click here)