The University of Arizona's Radiometric Calibration Test Site (RadCaTS): lessons learned after 10 years in operation at Railroad Valley, Nevada

The Radiometric Calibration Test Site (RadCaTS) was developed by the Remote Sensing Group of the Wyant College of Optical Sciences at the University of Arizona in the early 2000s. During the prototyping phase, RadCaTS was used to supplement the in situ data that were routinely collected by on-site personnel using the traditional reflectance-based approach. A data processing methodology was developed, tested, and compared to the reflectance-based results during this stage. The experience gained in this process resulted in the development of radiometrically-stable, all-weather, ground-viewing radiometers (GVRs), the first of which were deployed in 2012. Additional upgrades over the past ten years have included a satellite uplink station, upgraded Cimel CE-318T solar-lunar photometer, and a GVR with linear motion. This work provides an overview of RadCaTS, describes the lessons learned during the past ten years of operation, and also a summary of the radiometric calibration and validation results for such sensors as Landsat 7 ETM+, Landsat 8 and 9 OLI, Terra and Aqua MODIS, SNPP and NOAA-20 VIIRS, Sentinel-2A and -2B MSI, and GOES-16 and -17 ABI.