| Concept definition: |
The ratio, for a particular material <SURFACE> and unit solid angle about a particular reflection <DIRECTION>, of the reflected <<RADIANCE>> into that solid angle to the purely diffuse, total incident <<RADIANCE>> from the hemisphere above that <SURFACE>; integrated hemispherical hemispherical reflectivity. This quantity is also defined as the integral over the incident hemisphere of the BRDF times the cosine of the angle between the surface normal and the incidence <DIRECTION> times the differential incident solid angle. It is a function of the zenith and azimuth angles of the reflected light and is <<WAVELENGTH>>-band integrated, therefore the quantity is unitless and the particular band is specified separately. |
