The excess attenuation of electric field in the presence of deciduous trees

We present an approximation formula and numerical results for the excess attenuation of electric field of a wave propagating within deciduous forest. The formula is tuned to fit averaged attenuation obtained by full-wave simulations of stochastic 3D and 2D models of forests. The electric field was either vertically or horizontally polarized, at frequencies 30 MHz, 60 MHz and 100 MHz. The formula predicts the excess attenuation within several decibels, up to at least 100 MHz.