ABSTRACT
The last 25 years of remote sensing have led to great advances in our ability to monitor and model the land surface. However, current remote sensing techniques provide few of the quantitative measurements such as canopy cover, life form, large tree density, tree size (height and crown diameter), biomass, crown volume, height to live crown and vertical foliar diversity which are needed for detailed resource management. Important character istics of the land surface are related to vertical structure which is difficult to measure with optical and radar remote sensing, generally requiring modelling (e.g., see the extensive literature on invertible canopy models such as Ni et al., (1999)).
