\begin{table}%t1
\caption{ Figure of merit $FoM$ per Eq.~(\ref{eq:fom}) for the three different survey set ups
    as described in the text: Full Incoherent, Core Coherent and
    Superstation Coherent.  \label{tab:fom}}
\par
  %\centerline
{
  \begin{tabular}{lcccccc}
  \hline\hline
  Type     & ${A}/{T_{\rm sys}}$ (m$^2$/K)   & $N_{\rm beams}$ & $\Omega$ (deg$^2$) & $B$ (MHz)
 &  $1|N_{\rm stations}$  & $FoM$ \\
  \hline                                  		
  Full Incoherent        &    260          &1          & 27      &   32 &  54 &  1.0 \\ 
  Core Coherent          &    170          &128        & 0.006   &   32 &   1 &  0.8 \\
  Superstation Coherent  &     40          &128        & 0.23    &   32 &   1 &  1.2 \\
  \hline
  \end{tabular}}
  \medskip
\par
  All parameters derived using the lowest
    observing frequency, 120~MHz. In the first column,
    $A/T_{\rm sys}$, we use 54, 36 and 12 stations respectively,
    of 24 tiles at 28~m$^2$, and 140~K, while for the {\em Superstation
    Coherent} case we also multiply by 0.70 to correct for the lower
    sensitivity at the station beam edge. 
\end{table}