Electromagnetic wave interaction with coniferous trees: theory and experiment

A multilayer scattering model has been developed to investigate the relation between the tree architecture and the backscattering measurements from three kinds of coniferous trees at X-band. Each layer contains different types of scatterers to account for the tree components (leaves, branches, trunk). The Helmholtz integral along with the radiative transfer equations is used to calculate the phase matrices of the tree components and the backscattering coefficients of the trees. It is found that the echo area within any tree can be very different between VV and HH, especially at the tree top. For a group of trees. the levels of VV and HH are of the same order and their angular trend depends on the tree architecture. The main contribution to the backscattering coefficients is due to the branches.<>