Evaluation of early NOAA-20 VIIRS RSB radiometric performance using intercomparison with Aqua MODIS

The radiometric performance of the reflective solar bands (RSBs) of NOAA-20 VIIRS, recently launched on 18 November 2017, is evaluated through an intercomparison with Aqua MODIS. The analysis adapts a "nadir-only" refinement of the simultaneous nadir overpass (SNO) to generate comparison time series for assessment of the on-orbit calibration of NOAA-20 VIIRS RSBs using the official sensor data records (SDRs). The comparison result reveals an unstable and varying early radiometric performance upward of 5%. SNPP VIIRS, the precursor VIIRS, is also used to generate a comparison time series against Aqua MODIS. The result shows that NOAA-20 VIIRS RSBs have a 2 to 8% radiometric deficit relative to SNPP VIIRS RSBs.