CARABAS measurements of coniferous forest stem volume on sloping terrain

Low frequency SAR has shown good results for the retrieval of stem volume in coniferous forests, where the scattering strength is directly related to the volume of the trunk. However, since the scattering is dominated by the trunk-ground dihedral mechanism, it is also sensitive to the topography (i.e. angle between trunk and ground). Using data from CARABAS, we show how the backscattering is sensitive to the topography and radar viewing geometry. However, unlike higher frequencies, the VHF scattering from trees on moderate slopes is still dominated by the trunk-ground interaction.