Initial Analysis of Spectral Smile Calibration of Hyperspectral Imager Suite (HISUI) Using Atmospheric Absorption Bands

This paper reports on the initial analysis of spectral smile calibration Hyperspectral Imager Suite (HISUI) onboard International Space Station, which has been continuously acquiring data since September 4, 2020. HISUI is an optical hyperspectral imager consisting two subsystems: VNIR covering 400 to 980nm at intervals 10 nm, and SWIR 895 2481nm 12.5nm intervals. Based atmospheric correction for actual observation images, we assessed cross-track dependences wavelength deviation (spectral smile) full-width half-maximum (FWHM) response function. We found that significant was observed, with maximum variations 1.8nm in 4.3–4.5nm SWIR. In addition, variation FWHM observed 5.0nm 2.5–3.5nm SWIR.We used results model functions update a table internal system HISUI. Then, evaluated how reduce acquired after 27, 2021.We confirmed showed nearly flat profile within 0.25nm constant FWHM. For SWIR, although slight amount were still partly due dependence smile, reduced <~2.2 nm. study demonstrated using images ground surfaces important characterization sensors.