Prelaunch radiometric calibration of the J4 VIIRS thermal emissive bands

The Visible-Infrared Imaging Radiometer Suite (VIIRS) is a primary sensor on-board both the Suomi-National Polar-orbiting Partnership (SNPP) and Joint Polar Satellite System spacecrafts. SNPP, JPSS-1, and JPSS-2 VIIRS are currently on-orbit, JPSS-3 VIIRS is in spacecraft integration, and JPSS-4 VIIRS completed sensor level thermal vacuum (TVAC) testing in late 2023. TVAC testing covered the spatial, spectral, and radiometric performance of the sensor at three temperature plateaus on both the primary and redundant electronic sides. This paper will focus on the radiometric performance of the 7 thermal emissive bands (TEBs) that cover a spectral range of 3.7 to 12 μm. This includes key instrument performance parameters such as the gain, dynamic range, noise equivalent delta temperature, and absolute radiometric difference. It also includes the performance of the on-board calibrator blackbody (OBCBB). Finally, a comparison of the JPSS-4 VIIRS TEB radiometric performance with previous builds will be discussed. The results of the JPSS-4 VIIRS TVAC testing show that the TEB radiometric performance is consistent with the previous builds. The Sensor Data Record (SDR) quality from JPSS-4 VIIRS is expected to be similar to SNPP, JPSS-1 and -2 VIIRS.