\begin{table}%t1
 \caption{\label{noise}Lines of Nodes and BH~position estimates from noisy data.}
 \small%\centering
\par
 \begin{tabular}{c c c c}
   \hline \hline\noalign{\smallskip}
Model   & $x_{\rm BH}(\arcsec)$& $y_{\rm BH}(\arcsec)$ & $\theta_{\rm LON} (^{\circ})$  \\
   \noalign{\smallskip}\hline 
Noiseless   &0.00  &  0.00 &  0.00 \\
$S/N =20 $  & --0.01~$\pm$~0.02 &0.00~$\pm$~0.03& --5$~\pm$~4  \\
$S/N =50 $   & 0.00~$\pm$~0.01 &0.00~$\pm$~0.01 & --1~$\pm$~1  \\
$S/N =100$   & 0.015~$\pm$~0.008 &--0.003~$\pm$~0.008 & --0.9~$\pm$~0.8  \\
   \hline
 \end{tabular}
\end{table}