S-NPP VIIRS thermal emissive band thermal calibration errors and their impact on blackbody warm up and cool down f factors

The Visible-Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (S-NPP) spacecraft as a primary sensor was launched October 28, 2011. There are 22 VIIRS bands: 7 thermal emissive bands (TEBs), 14 reflective solar bands (RSBs) and a Day Night Band (DNB). An on-orbit On-Board Calibrator BlackBody (OBCBB) is used as the TEB calibration source that tracks the detector gain change on a scan-by-scan basis. A thermal model to account for internal sensor emission is used in both the OBCBB derived gain calibration and Earth View (EV) radiance and brightness temperature retrievals. This thermal model uses pre-launch calibration coefficients to convert detector response into radiance and internal VIIRS cavity thermistors to estimate the sensor's internal emission from various optical surfaces. The inputs to the thermal model have uncertainties which introduce errors in both the gain correction and the EV retrievals. This paper will discuss the impacts of the thermal model uncertainties on the VIIRS calibration.