NIR reflectance spectra of water ice with varying grain size and temperature

An experimental facility has been set up to acquire infrared spectra of pure water ices with controlled grain sizes ranging from 80 to 700 µm and temperatures ranging from 80 to 140 K at 0.01 mbar. Forty-seven near IR spectra (1.0–5.0 µm), selected among the total acquired spectra, permit us to determine how spectral characteristics between 1.0 and 1.8 µm depend on both grain size and temperature.