In roadway lighting:

A table of reduced luminance coefficient values (see Section 11.5.20) for a category of pavement. Values in the table are dependent on the variables β and tan γ, where β is 180 minus the angle (as seen in plan view) between the line from the observer to the point of infinitesimal size and the line from the luminaire to the point, in degrees. The value of tan γ is the distance along the plane of the road under the luminaire to the discrete point, divided by the mounting height of the luminaire. (See figure.)

The factors given in the table have been multiplied by 104. This multiplying factor, MF, is divided out in the formula for roadway luminance at the point.

NOTE: This term was added in RP-16-17 Addendum 3.


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