Current commercial airborne laser scanners are being used extensively in Australia and throughout the world for the definition of ground surface digital elevation models. Interest in the use of such instruments for measuring forest canopy height, foliage cover and foliage profiles is also rapidly increasing. The effectiveness of these instruments depends on the spatial density of the Lidar pulses and the number of return signals sampled per pulse. Nevertheless, by effective processing there is a great deal of useful information to be obtained from data gathered using conventional terrain Lidar instruments.

The vertical distribution of canopy components is a valuable parameter for the characterisation of forest light microclimates and rainfall interception, which can in turn be used to model forest growth. Terrain Lidar provides a limited but useful sample of pulse return power necessary to define foliage cover profiles.

Canopy Lidar instruments digitise the complete return pulse of the Lidar signal, providing much more detailed information about the distribution of the canopy elements along a vertical path through the canopy. A number of datasets from NASA’s experimental airborne canopy Lidar system SLICER have been processed to help validate algorithms and software being developed by the CLI.