 Bi-hemispherical reflectance

Bi-hemispherical reflectance is a measure of how much light is reflected by a surface when illuminated from all directions over a hemisphere and then measured from another hemisphere. It is typically expressed as a ratio or percentage of the incident light that is reflected. In more detail: - **Bi-hemispherical** refers to the two hemispheres involved in the measurement: the hemisphere from which light is incident and the hemisphere from which the reflected light is measured.