https://doi.org/10.1351/goldbook.I03254
Radiant power
, Notes:
- Mathematical definition:
. If theradiant poweris constant over the surface area considered, . - Alternative definition: Integral, taken over the hemisphere visiblefrom the given point, of the expression
, where is theradianceat the given point in the various directions of the incident elementary beams of solidangle and is theanglebetween any of the beams and the normal to the surface at the given point. - This term refers to a beam not scattered or reflected by the target or its surroundings. For a beam incident from all directions, fluence rate(
) is an equivalent term. where is thespectral irradianceatwavelength .