A Status of JPSS-3 VIIRS Radiometric Performance Based on Ground Testing

The Joint Polar-orbiting Satellite System (JPSS)-3 Visible Infrared Imaging Radiometer Suite (VIIRS) has completed a large portion of its ground test program. The VIIRS series includes two sensors successfully operating on-orbit onboard the Suomi National Polar-orbiting Partnership (SNPP) and JPSS-1 satellites and a third sensor, currently integrated into the JPSS-2 satellite, is undergoing observatory level testing. VIIRS was designed to take high quality measurements of Earth's surface from low Earth orbit which are (or will be) used to generate a large set of environmental data products important in science. To ensure that the VIIRS instruments generate these high quality measurements once on orbit, each sensor undergoes an extensive ground test program at the component, sensor, and observatory levels. The main calibration of the instruments occurs at the sensor level and includes radiometric, spectral, and geometric performance (this paper will not discuss the geometric calibration). A series of design requirements are tested against to ensure that the sensor performs with sufficient fidelity to provide the level of data quality that the science community demands, including dynamic range, SNR, polarization, stray light performance, and spectral characteristics. In addition, a number of instrument characteristics must be characterized on the ground in order to transfer the calibration from the calibrated ground sources to on-orbit, including radiometric gain and response versus scan angle. This work focuses on the performance of the JPSS-3 VIIRS instrument derived from recent instrument level ground testing (under both ambient and environmental conditions), and compares that performance to previous builds. The sensor characterization and calibration estimates derived by the independent government team will be used to verify compliance with the sensor requirements and to generate a set of metrics necessary for on-orbit calibration.