Salar de Uyuni Field Campaign for Independent GOES-17 ABI Solar Reflective Channel Radiance/Reflectance Validation

A field campaign was held at Salar de Uyuni, Bolivia in September 2018 to take measurements for an independent validation of the GOES-17 Advanced Baseline Imager (ABI) solar reflective channel radiometric and reflectance scale. The reflectance-based approach of vicarious calibration is used in this work: In situ measurements are taken to characterize surface reflectance and the atmosphere to constrain radiative transfer code to predict at-sensor radiance and reflectance. A 1-km square test site was identified in the north-central portion of the salt flat based on historic uniformity analysis. The geometry of the ground-based reflectance measurements was designed to match the GOES-16 and GOES-17 view geometries and be coincident with several image acquisitions over the 90-minute period of reflectance measurements. A sun photometer from the Aerosol Robotic Network (AERONET) was used to take measurements at the reflectance site for derivation of atmospheric properties such as aerosol optical depth, angstrom parameter, and columnar water vapor. This work will 1) compare at-sensor reflectance and radiance of the test site reported by GOES-16 and -17 ABI with the predicted values based on the field measurements described above; and 2) provide characterization of the Salar de Uyuni site to assist future sensor intercomparisons.