Wiener filter method applies deconvolution on antenna temperature $tA(\theta E,\phi E)$ to obtain higher spatial resolution images. Assuming that IFOV is invariant in the observation, $Fn(\theta E0,\phi E0)(\theta E,\phi E)$, which is independent with observed location can be expressed by $Fn(\theta E,\phi E)$. Equation (1) can be expressed as convolution of $tB(\theta E,\phi E)$ and $Fn(\theta E,\phi E)$, Display Formula
$tA(\theta E,\phi E)=tB(\theta E,\phi E)\u2297Fn(\theta E,\phi E)+n(\theta E,\phi E),$(2)
where $\u2297$ defines the convolution and $n(\theta E,\phi E)$ is the noise of radiometer. Then, applying Fourier transform on the both side of Eq. (2), we obtained Display Formula$TA(u,v)=TB(u,v)H(u,v)+N(u,v),$(3)
where $TA(u,v)$, $TB(u,v)$, $H(u,v)$, and are Fourier expressions of $tA(\theta E,\phi E)$, $tB(\theta E,\phi E)$, $Fn(\theta E,\phi E)$, and $n(\theta E,\phi E)$, respectively. Finally, an inverse operator $W(u,v)$ is used to reconstruct the ground brightness temperature $TB(u,v)$: Display Formula$TB\u2032(u,v)=W(u,v)TA(u,v).$(4)