Variance in bidirectional reflectance over discontinuous plant canopies

An exploratory study on the the spatial variance of the bidirectional reflectance over discontinuous plant canopies indicates that the spatial variance of the bidirectional reflectance calculated from ASAS images has peak values at the hotspot and near nadir. This behavior can be explained by the geometric effect of discontinuous tree crowns and the regularization effect. Validation of Jupp and Woodcock´s two component geometric optical (GO) model shows that it captures the basic features of the spatial variance of the bidirectional reflectance over discontinuous plant canopies. Their two-component GO model is modified to account for the spatial interactions of four scene components. Validation shows that the modified GO model improves the model prediction. This exploratory study helps lay the foundation for future retrieval of surface information from remote sensing satellite data