Spectrum Vis-NIR bidirectional reflection spectrum (i=40°, e=10°, az=140°) of simulated slab ice 2.2 mm thick on snow at −3°C Spectrum Vis-NIR bidirectional reflection spectrum (i=40°, e=20°, az=45°) of simulated slab ice 7.5 mm thick on snow at −3°C Spectrum Vis-NIR bidirectional reflection spectrum (i=60°, e=0°, az=180°) of simulated slab ice 11.4 mm thick on snow at −3°C