Human-in-the-Loop Radiometric Update Process for GOES-R ABI L1b Products

The Advanced Baseline Imager (ABI), the premier instrument for NOAA’s Geostationary Operational Environmental Satellite-R (GOES-R) series, provides high-quality, radiometrically-calibrated Earth-observing imaging data. The radiometric performance with the nominal calibration process in the six visible/near-infrared (VNIR) wavelength bands has been within requirements, but to fully utilize the exceptional potential of the products requires optimizing the process. The challenge then becomes to balance fulfilling this potential performance without negatively impacting operational overhead. This paper describes how this challenge was answered by two process changes. First, the cadence of solar calibrations was increased from quarterly to bi-weekly to better characterize the instrument trending. Second, the original the ground processing algorithm automatically updated the calibration coefficients for the thousands of VNIR detectors after each solar diffuser observation. These automatic updates can work well, but it has been recognized that having “humans in the loop” (HitL) are necessary for the long-term maintenance of the L1b products. This second change became effective in 2023, however, this is more than just a code change: it involves coordinating the efforts of several teams to make sure this transition from research-level idea to a reliable, sustainable operational activity. We will also show how the HitL process is being successfully used in the production of GOES-16 ABI L1b products since April 2024.