Optimal solar/viewing geometry for an accurate estimation of leaf area index and leaf angle distribution from bidirectional canopy reflectance data

Abstract. An analysis of the accuracy in the estimation of agronomic parameters such as leaf area index (LAI) and leaf angle distribution (LAD) from the bidirectional canopy reflectance (BDCR) data is presented. This analysis shows that for a given level of errors in the data, there are certain preferred illumination and viewing directions for which the estimations are most accurate. There are other directions, e.g. nadir viewing, for which estimates can be significantly erroneous. This analysis should be useful in selecting the optimum illumination and viewing directions for off-nadir viewing remote-sensing systems such as the SPOT satellite and the Multispectral Linear Array (MLA) Shuttle.