Radiant fluence rate, or spherical irradiance, is equal to the total radiant flux incident on a small sphere divided by the area of the diametrical cross-section of the sphere.
Applicable units are those of quantitykind:PowerPerArea
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Radiant fluence rate, or spherical irradiance, is equal to the total radiant flux incident on a small sphere divided by the area of the diametrical cross-section of the sphere.
$E_0 = \int{L}{d\Omega}$, where $d\Omega$ is the solid angle of each elementary beam passing through the given point and $L$ its radiance at that point in the direction of the beam.