Correction of NOAA-20 VIIRS day/night band low-gain stage gain calibration errors by scaling factors derived from prelaunch testing data

The operational VIIRS Day/Night Band (DNB) Low Gain Stage (LGS) gain is calibrated by the onboard solar diffuser when it is fully illuminated by the Sun. Such calibration method relies on assumption of the same calibrator view and Earth view responses of the LGS. However, analysis of the NOAA-20 VIIRS DNB prelaunch testing data shows this assumption is not valid for all aggregation modes and detectors, consequently yielding striping in NOAA-20 VIIRS DNB daytime images collected by its LGS. Through applying scaling factors derived from the prelaunch testing data, the operational LGS gain calibration errors are corrected and striping in the reprocessed DNB daytime images is reduced.