Calibration of the GOES 6-16 high-energy proton detectors based on the GLEs modeling

The Geostationary Operational Environmental Satellites (GOES) series provide both real-time and historical data for radiation exposure estimation and solar proton radiation environment modeling spanning several decades. Recently, several groups conducted calibration studies that significantly reduced the uncertainties on the response of GOES detectors, thus improving the reliability of the spectroscopic observations of solar energetic particle events. In this work, the long-established Band function fitting for past Ground Level Enhancements (GLEs) and their recent revision are used as references to estimate the best matching energies of all proton channels of GOES 6-16 except for P1, with emphasis on comparing previous calibration studies on the high energetic proton measurements. The calculated energies for different missions in the same series (GOES 8, 10, 11) show overall consistency but with small variations, and the differences among missions of the different series are noticeable for the measurements crossing the past 3 solar cycles, though the results are sensitive to the way to subtract the background fluxes. The discrepancy and agreement with previous calibration efforts are demonstrated with other independent analyses. It is verified that the integral channel P11 of GOES 6-16 can be reliably used as a differential proton channel with an effective energy of about 1 GeV. Therefore, the multi-decade in situ measurements of GOES series can be utilized with more extensive energy coverage to improve the space radiation environment models.