The exitance of an extended surface is the rate at which it is radiating energy (in all directions) per unit area. The usual symbol is M and the units are W m⁻² . It is an intrinsic property of the...The exitance of an extended surface is the rate at which it is radiating energy (in all directions) per unit area. The usual symbol is M and the units are W m⁻² . It is an intrinsic property of the radiating surface and is not dependent on the position of an observer.
The factor sinϑdϑdφ is an element of solid angle, dω, and the factor cosϑ is needed to convert the projected area of radiance back into physical area. \...The factor sinϑdϑdφ is an element of solid angle, dω, and the factor cosϑ is needed to convert the projected area of radiance back into physical area. πF=∫2π0∫2π0L(ϑ,φ)sinϑcosϑdϑdφ=∫2π0∫1−1L((μ,φ)μdμdφ
