RET input parameter estimation for a generic model of propagation through vegetation using excess attenuation and phase function measurements

A new model for radiowave propagation through vegetation has been developed by four consortium members under a contract by the UK Radiocommunications Agency (RA). This generic model combines an edge diffraction and ground reflection model with a direct (through vegetation) signal modelled through the application of the theory of radiative energy transfer (RET). RET predicts attenuation vs foliage depth using parameters to describe the absorption and scatter cross-section, albedo, and scatter function of the vegetation. These parameters are determined empirically for each vegetation type, by fitting RET curves to the measurements. The paper, after a brief introduction to the generic model, addresses possible ways of obtaining these input parameters.