\begin{table}%t1
%\centering
\par
\caption{\label{table-obs}Information on the averaged data. Each line of the table corresponds to one average.}
\begin{tabular}{ccccc}
\hline\hline
Date & Number of & Number of & Polarimetric & Total \\
   & images & accumulations & accuracy & duration \\
   &   & per image &   & (s) \\
\hline
5.7.2008 & 10 & 16 & 2.5E-04 & 189 \\
5.7.2008 & 8 & 16 & 2.8E-04 & 151 \\
5.7.2008 & 8 & 16 & 2.8E-04 & 151 \\
5.7.2008 & 21 & 16 & 1.7E-04 & 397 \\
5.7.2008 & 21 & 16 & 1.7E-04 & 397 \\
5.7.2008 & 9 & 16 & 2.6E-04 & 170 \\
5.7.2008 & 25 & 16 & 1.6E-04 & 473 \\
5.7.2008 & 14 & 16 & 2.1E-04 & 265 \\
5.7.2008 & 19 & 16 & 1.8E-04 & 359 \\
6.7.2008 & 15 & 32 & 1.4E-04 & 500 \\
6.7.2008 & 15 & 32 & 1.4E-04 & 500 \\
6.7.2008 & 15 & 32 & 1.4E-04 & 500 \\
\hline
\end{tabular}
\end{table}