The European optical goniometric facility: technical description and first experiments on spectral unmixing

Presents the new European goniometric facility installed at the Joint Research Center of the Commission of the European Union. Basically, this system allows independent positioning of a light source and a detector anywhere on a 2 m radius hemisphere centered on the target and thereby to perform bidirectional reflectance measurements. The control software allows full programming of an experiment, the graphical visualization of the measurement geometry and the interface to a dedicated data base for the experimental results. A first experiment is described in which multispectral CCD camera images were acquired on various targets (soils, canopies and synthetic leaves) under different illumination angles. The purpose was to provide a data set allowing the comparison of the projected area of spectral endmembers, as measured from the CCD images, with the result of linear spectral mixture inversion algorithms