A NEW FOREST LIGHT INTERACTION-MODEL IN SUPPORT OF FOREST MONITORING

Landsat TM data may be of use for forest timber and vitality monitoring. Literature study reveals inconsistent results of techniques based on spectral indices and regression. Existing models appear incomplete because they do not account for shadowing between trees, or because they treat trees as opaque bodies. For this reason a new forest light interaction model has been developed. It accounts for both shadowing and crown transparency. The inverse model has been implemented as an image processing algorithm. Model results are studied and compared with ground data from the Kootwijk forest in The Netherlands. Results indicate that the model gives a fair representation of reality. In this respect, the utility of the NDVI is also discussed. More research is necessary for further validation.