Spectrum Vis-NIR bidirectional reflection spectrum of spherical water ice particles 67±31 μm at 223 K Spectrum Vis-NIR bidirectional reflection spectrum of spherical water ice particles 4.5±2.5 μm at 223 K Spectrum Vis-NIR bidirectional reflection spectrum of spherical water ice particles 4.5±2.5 μm at 223 K, after 50 min of metamorphism Spectrum Vis-NIR bidirectional reflection spectrum of spherical water ice particles 67±31 μm at 173 K Spectrum Vis-NIR bidirectional reflection spectrum of spherical water ice particles 67±31 μm at 173 K, after 12h of metamorphism Spectrum Vis-NIR bidirectional reflection spectrum of spherical water ice particles 4.5±2.5 μm at 173 K Spectrum Vis-NIR bidirectional reflection spectrum of spherical water ice particles 4.5±2.5 μm at 173 K, after 48h of metamorphism Spectrum Vis-NIR bidirectional reflection spectrum of spherical water ice particles 2 to 100 μm at 173 K Spectrum Vis-NIR bidirectional reflection spectrum of spherical water ice particles 2 to 100 μm at 173 K, after 18h of metamorphism