Radiative flux
= Radiative flux
{title2=$F_\nu$}
Radiative flux is the first angular moment $F_\nu=\int I_\nu\cos\theta\,d\Omega$ of <specific intensity> and measures net radiant <power> crossing unit area. Integrating over <frequency> gives bolometric <radiative flux>. The receiving surface's orientation matters through $\cos\theta$; <observed radiative flux> from a compact distant source conventionally refers to an area perpendicular to its <line of sight>.