BRDF laboratory measurements

Laboratory studies of the bidirectional reflectance distribution function (BRDF) have greatly improved our understanding of the bidirectional reflectance characteristics of natural and man‐made surfaces. Explorative research and model validation studies in astronomy, remote sensing, material science, and computer graphics have likewise increased the knowledge of BRDF and its relationship to surface properties. In this review, a concise summary of laboratory BRDF studies relevant to remote sensing is given along with a discussion of major advantages and drawbacks of laboratory BRDF experiments and an overview of laboratory goniometric radiometers. Recommendations made for future research directions include the standardization of BRDF laboratory measurements, the initiation of hyperspectral BRDF databases for multidirectional endmember spectra, and the investigation of the BRDF phenomenon at different levels of scale by jointly analyzing laboratory, field, and remote sensing data.