Comparing Hyperion-Observed with Model-Predicted Lunar Irradiances in Support of GOES-R ABI Calibration

Photometric stability of the lunar surface and its relatively smooth reflectance spectra makes the moon an attractive target for calibrating satellite instruments. In this paper, we report analysis of Hyperion lunar observations and comparison with Miller-Turner (MT2009) lunar irradiance model. Hyperion is a hyper-spectral imager on-board the Earth Observing One (EO-1) with 242 spectral channels covering the visible and nearinfrared. It made observations of the moon regularly with a phase angle mostly at 7 degree. On the other hand, The MT2009 model was developed to quantify spectral irradiance by incorporating solar irradiance and lunar spectral albedo data. The model is parameterized to account for Sun/Earth/Moon geometry and lunar phase. We analyzed 5 Hyperion lunar observations and evaluated lunar irradiance and reflectance derived from Hyperion with the MT2009 model. The overall lunar reflectance difference between Hyperion derivation and MT2009 model is 5-10%. Through reflectance comparison, we also identified issues in two strong atmospheric water absorption bands in the Hyperion observation. Hyperion lunar observation also provides opportunity to integrate the hyperspectral data to produce synthetic bands equivalent to bands of interest, such as the ABI bands. Examples are presented to demonstrate using model derived from Hyperion and MT2009 to support lunar calibration of GOES-R ABI instrument