\begin{table} %t1
\caption{\label{table:ladc}Configurations for LAD compensation.} 
\small 
%\centering
\par
\begin{tabular}{cr c c r } 
\hline\hline 
{Total delay} &  B1 & B2  & $\Delta t$ \\
(m) & &  &   \\ 
\hline 
$-120{-}{-72}$ & ${\rm S3}_4$ & ${\rm S3}_2$ & +2  \\ 
$  -72{-}{-24}$  & ${\rm S3}_4$ & ${\rm S3}_3$ & +1  \\ 
$  -24{-}{+24}$ & S0 & S0 & 0  \\ 
$ +24{-}{+72}$  & ${\rm S3}_1$ & ${\rm S3}_2$ & --1  \\ 
$ +72{-}{+120}$ & ${\rm S3}_1$ & ${\rm S3}_3$ & --2  \\ 
\hline  
\end{tabular} 
\end{table}