\begin{table}%ta.1
\caption{\label{tab:instab_noi}Limiting rms OPD values computed for a G2V star located at 15~pc such that shot noise dominates instability noise by a factor~5.}
\par
%\centerline
{ \small \begin{tabular}{lccllccccccccc}%14
  \hline \hline
$\sigma_{\rm OPD}$ [nm] &\multicolumn{6}{c}{2-m apertures} & \multicolumn{6}{c}{4-m apertures} \\
%\hline
&&& $\lambda = 7~\mu$m & &  $\lambda =10~\mu$m & && &$\lambda =7~\mu$m & & & $\lambda = 10~\mu$m & \\ 
&$\sigma_{\rm amp}$ &DCB & X-ar2 & X-ar6 & DCB & X-ar2 & X-ar6 & DCB & X-ar2 & X-ar6 & DCB & X-ar2 & X-ar6\\
\hline
White noise$^a$ & 0.01\% & $>$50&$>$50&$>$50&$>$50&$>$50&$>$50&$>$50&$>$50&$>$50&$>$50&$>$50&$>$50\\
&  0.05\% & 16 & 9.5 & 9.5 & $>$50 & $>$50 & $>$50 & 6.5 & 4.6 &4.6& 23 & 16 & 16  \\
&0.10\% & 2.4 & 1.0 &  1.0 & 5.3 & 4.8 & 4.8& 0.8& 0.5 &0.5 &3.7 &2.9 &2.9\\
\hline
1/f noise$^b$ & 0.01\% &0.7 &2.6 &4.2 &2.8 &13 &19 &0.4 &1.1 &1.9 &1.1 &3.6 &5.6\\
&0.05\% & 0.7&0.9&1.5&2.0&2.9&4.1&0.3&0.4&0.6&0.8&0.9&1.4\\
&0.10\% & 0.5&0.5&0.7&1.5&1.6 &2.0 &0.3&0.3&0.3& 0.5&0.5&0.6\\
\hline
\end{tabular}}
\medskip
$^a$ rms values is defined on the [0--10~Hz] wavelength range;  $^b$ rms values is defined on the [1/$t_{\rm rot}$-10$^4$~Hz] wavelength range.
The results are given at 7~$\mu$m and 10~$\mu$m, assuming a spectral resolution of 20, for different rms amplitude mismatches and shapes of the instability noise power spectrum. Three configurations are shown, the X-array with an aspect ratio of~2 (X-ar2), the X-array with an aspect ratio of 6 (X-ar6) and the Dual Chopped Bracewell (DCB, configuration used in \citealt{Lay:2004}).
\vspace*{5mm}  
\end{table}