The InfraSnow Sensor was developed in close collaboration with the Swiss Federal Institute for Snow and Avalanche Research (SLF) in Davos. This is the first hand-held device that can measure snow specific-surface-area (SSA) at fractional cost of existing bulky laboratory devices.
The method consists of diffuse near-infrared reﬂectance measurements using a compact integrating sphere setup to derive SSA. Diffuse reﬂectance is measured at NIR wavelengths, where impurities have only a weak inﬂuence on the reﬂectance of snow. For a sufﬁciently thick snow block, there exists a unique correlation between diffuse hemispherical reﬂectance and SSA according to multiple-scattering radiative transfer theory.
Gergely, M., Wolfsperger, F., and Schneebeli M., 2014: Simulation and Validation of the InfraSnow: An Instrument to Measure Snow Optically Equivalent Grain Size. IEEE Transactions on Geoscience and Remote Sensing.
Wolfsperger, F.; Rhyner, H.; Schneebeli, M., 2018: Pistenpräparation und Pistenpflege. Das Handbuch für den Praktiker. 232 p., WSL-Institut für Schnee- und Lawinenforschung SLF