Long distance path-loss estimation for wave propagation through a forested environment

Accurate modeling of wave propagation behavior through forested environments is of great interest for civilian and military communication applications. Existing foliage propagation models treat the forest as an effective lossy dielectric medium and predict an exponential increase of path-loss with respect to the propagation distance within the forest. Such a model captures only the coherent power of the signal and neglects the incoherent power from the field fluctuation due to the random distribution of scatterers, such as brranches and leaves, within th forest. For long distance communication, such incoherent power tends to dominate the overall received power after a certain distance. Experimental results show that the simple models grossly overestimate the path-loss. A new Statistical WAve Propagation (SWAP) model, based on coherent wave theory and a renormalization approach, is presented and is shown to provide a reasonably accurate and computationally efficient solution for the estimation of path-loss in a forested environment over long distances.