Intercepted Snow Impacts on Boreal Forest Transmission at 2.4 GHz

At UHF and above, propagation losses in foliage can quickly become significant for forest transmission paths. Several well-known models exist to predict these losses as functions of transmission path length, foliage type, and frequency. However, the vast majority of measurements performed to supply the parameters within these models have been conducted in temperate forests, and in forests without any intercepted precipitation. High latitude boreal forests are fundamentally different in that they maintain foliage year-round, and commonly support significant amounts of intercepted snow throughout the winter season. This work describes the winter-season measurements at 2.4 GHz, conducted with the goal of determining if intercepted snow (or changes driven by ambient temperature and/or insolation) could impact radio transmission through boreal forests. Our results suggest that wet intercepted snow, and post-snowfall melting of dry intercepted snow, can lead to additional losses of up to 50 dB over a ~100 m path through a dense, white spruce forest.