Hello, a colleague of mine forwarded me this email as I deal primarily with lidar services at NGI.
In terms of snow and ice lidar data collection, the optimal wavelength is around 1024 nm. The issue with longer wavelengths is their high absorption by water. The 1570nm will be as you say much more eyesafe, but you should
not expect to get many returns. Depending on snow conditions you may get good returns directly under the platform, as long as there is not a ice cover that will act as a pure reflector and saturate your instrument.
Sorry it is not so clear, but this is a tricky situation you are working with.
Regards, Matt Lato
med vennlig hilsen for Norges Geotekniske Institutt (NGI)