Measurements of transmittance through falling snow were made in the visible, 3-5 μm and 8-12 μm bands along a 540 m path. In the visible, measurements were made for both a narrow (0.05 mrad) and wide (3mrad) transmitted beam detected by a common receiver. The apparent path averaged extinction, derived from the transmittance measurements using the Beer- Bouguer law, was found to be dependent upon wavelength and transmissometer geometry. The results may be explained by taking into account scattered contributions to the measured transmittance. The results are compared to calculations made with a single-scattering model and a multiscattering model.
D. L. Hutt,
L. R. Bissonnette,
D. St. Germain,
"Multi-Wavelength Transmittance Through Falling Snow", Proc. SPIE 1115, Propagation Engineering, (11 October 1989); doi: 10.1117/12.960878; https://doi.org/10.1117/12.960878