= System-equivalent flux density
{title2=$\mathrm{SEFD}=2k_BT_{\rm sys}/A_e$}
= SEFD
{c}
{synonym}
The <system-equivalent flux density> is the unpolarized <spectral flux density> that would produce an <antenna> <temperature> equal to $T_{\rm sys}$. With effective collecting area $A_e$, $\mathrm{SEFD}=2k_BT_{\rm sys}/A_e$. The factor two follows from one <polarization of waves> measurement of an unpolarized source. State effective area and <polarization of waves> conventions when comparing sensitivities.<Sensitivity by Joan Wrobel>[slides 5–7, antenna performance and SEFD]{ref}
Back to article page
