Potential of multiangular spectral measurements to characterize land surfaces: Conceptual approach and exploratory application

New sensors exhibiting advanced technical specifications motivate the development of improved algorithms to take advantage of the enhanced performances of these sensors. In the particular case of the Multiangle Imaging Spectroradiometer (MISR) instrument, the angular sampling of the scattered radiance field, coupled with high spatial resolution and accurate radiometric calibration, justifies the implementation of physically based algorithms to optimally interpret the data and extract high-level information. This paper proposes a new approach to the reliable and accurate characterization of vegetated areas on the basis of data gathered in space and to the delivery of improved products to meet increasingly demanding user requests. An exploratory study based on advanced very high-resolution radiometer (AVHRR) data shows the potential of approaches based on advanced models but also points out the limitations associated with the use of data from monodirectional instruments. By contrast, a preliminary investigation conducted with synthetic MISR-like multiangular data illustrates the potential of analyzing data of high radiometric quality with advanced models to move toward a more complete characterization of terrestrial surfaces.