\begin{table}%t1
\caption{\label{tab:data}Some characteristic parameters of the different data sets of the campaign.}
%%\centerline

{\small
\begin{tabular}{cccc}
\hline  \hline
Night & Observation Window [MJD] & $t_{\rm eff}$ [h] &ZA [$^{\circ}$] \\
\hline
April 22, 2006 & $53~847.97679 {-} 53~848.01460$ & 0.76 & 18--28 \\
April 24, 2006 & $53~849.96428 {-} 53~850.00669$ & 0.99 & 16--28 \\
April 25, 2006 & $53~850.92813 {-} 53~850.99607$ & 1.53 & 10--26 \\
April 26, 2006 & $53~851.92862 {-} 53~852.00383$ & 1.64 & 10--29 \\
April 27, 2006 & $53~852.93474 {-} 53~853.00047$ & 1.42 & 12--28 \\
April 28, 2006 & $53~853.88173 {-} 53~854.01394$ & 2.23 & 10--32 \\
April 29, 2006 & $53~854.89514 {-} 53~855.04119$ & 2.78 & \phantom{0}9--41 \\
April 30, 2006 & $53~855.97283 {-} 53~855.97906$ & 0.16 & 23--24 \\
June 14, 2006  & $53~900.91979 {-} 53~900.95532$ & 0.80 & 43--52 \\
\hline
\end{tabular}}
\tablefoot{$t_{\rm eff}$ denotes the effective observation time. ZA gives the zenith angle range of the observations.}
\end{table}