Bidirectional Reflectance Distribution Function

sandy beach

Bi-directional Reflectance Distribution Function

            The Bi-directional reflectance distribution function (BRDF) describes how a surface would send light when illuminated from different directions. The BRDF is one of the crucial parameters needed in radiative transfer modeling and remote sensing. In recent years, we have made extensive BRDF measurements on various types of particles from perfect spheres to natural sediments. Below is a brief summary of the goals of our previous and current ONR supported BRDF research programs:
misc Development of an underwater instrument for in-situ BRDF measurement and take in-situ BRDF data
misc Find an analytical model to parameterize the in-situ BRDF data to supply radiative transfer models
misc Dependence of the reflectance on the sample thickness
misc Measurement of a surface composed of spherical particles (controlled laboratory measurements)
misc Effect of pore liquid index of refraction
misc Effect of pore liquid absorption coefficient
misc Polarized BRDF/transmission measurements and polarization opposition effects in sediment layers
misc Ray-tracing approach to predict sediment BRDF
misc Equifinality study on BRDF

Work Completed and Refereed Publications

misc Developed a BRDF-meter capable of doing both in-situ underwater and laboratory BRDF measurements
         Paper title:  "An instrument to measure the Bi-directional reflectance distribution function (BRDF) of surfaces"
         Journal: Applied Optics 39, 6197-6206 (2000)
           Full Article
misc Made in-situ benthic BRDF measurements during CoBOP field experiments and parameterized data
         Paper title: "Bi-directional reflectance measurements of sediments in the vicinity of Lee Stocking Island, Bahamas"
         Journal: Limnology and Oceanography 48, 380-389 (2003)
            Full Article
misc Determined the influential depth of BRDF measurements on sediment particle layers
         Paper title: "Determining the influential depth for surface reflectance of sediment by BRDF measurements"
         Journal: Optics Express 11, 2654-2665 (2003)
           Full Article
misc Performed BRDF measurements on prepared particulate surfaces and compared with radiative transfer models
         Paper title: "Comparisons of BRDF Measurements on prepared particulate surfaces and radiative transfer models"
         Journal: Applied Optics 44, 597-610 (2005)
           Full Article
misc Additional work completed with collaborators
        Paper title: "Effects of optically shallow bottoms on upwelling radiances: bidirectional reflectance distribution function effects"
        Journal: Limnology and Oceanography 48, 337-345 (2003)
           Full Article