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