OPTICAL REMOTE-SENSING OF VEGETATION - MODELING, CAVEATS, AND ALGORITHMS

The state-of-the-art on radiative transfer modeling in vegetation cano pies and the application of such models to the interpretation and anal ysis of remotely sensed optical data is summarized. Modeling of top-of -the-atmosphere and top-of-the-canopy radiance field is developed as b oundary value problems in radiative transfer. The parameterization of the constituent functions with simple models and/or empirical data is outlined together with numerical solution methods and examples of resu lts of model validation. Caveats in the assignment of signal character istics to surface properties are itemized and discussed with example r esults. Algorithms to estimate surface properties from remote observat ions are classified as spectral vegetation indices, model inversion, e xpert systems, neural networks, and genetic algorithms. Their applicab ility is also discussed.