INVERTIBILITY OF A 1-D DISCRETE ORDINATES CANOPY REFLECTANCE MODEL

The invertibility of an accurate discrete ordinates canopy reflectance model is investigated through a series of experiments. Effects of dif ferent canopy types, noise levels, spectral ranges, and sampling geome tries [including the NOAA Advanced Very High Resolution Radiometer (AV HRR) and the proposed Multi-angle Imaging SpectroRadiometer (MISR) sat ellite sampling schemes] are considered. Both error-free synthetic bid irectional reflectance data and empirical field reflectance data are u tilized. Results suggest that the model can retrieve soil and canopy p arameters with reasonable accuracy in most cases, and surface state pa rameters (absorbed radiation, spectral albedo and photosynthetic effic iency) with high accuracy in all cases. The efficiency of several comm only used optimization algorithms is also assessed, and a model sensit ivity study is conducted.