Use of automated in-situ measurements for sensor harmonization

Abstract:

Vicarious calibration approaches using in-situ measurements saw first use in the early 1980s and have since improved to keep pace with the evolution of the sensors that are being calibrated. The advantage to in-situ measurements is that they lead to a well-demonstrated and traceable accuracy. The drawbacks are the costs and labor-intensive nature of those approaches. The development of multi-platform constellations and the need to ensure radiometric consistency across them has led to the implementation of automated ground sites and the accuracy of the results from these automated sites make them suitable for harmonizing the radiometric output from multiple sensors. The results shown here applied to instruments from NASA’s Terra platform as well as Landsats 7 and 8 demonstrate the utility of automated sites as well as the feasibility of making the data from such sites more widely available to the instrument teams. The accuracy of the calibration for a single sensor typically meets the calibration requirements for most earth imagers and harmonization to better than 1% is feasible.