\begin{table}%t8
 \caption{\label{table:wbrmap}rms of the white noise reference baseline maps.}
 %\centering
\small
 \begin{tabular}{ccccc}
 \hline\hline
 &&&& \\[-8pt]
 $\tbase$ & $I_{\rm rms}$ & $ \langle\langle\sum_n n^2f_n\rangle\rangle$
 & $Q_{\rm rms}$ & $U_{\rm rms}$ \\
            & ($\mu$K) &  & ($\mu$K) & ($\mu$K) \\
 \hline
 2.5 s   & 4.947 & 1.542 & 6.974 & 7.072 \\
 15 s    & 2.006 & 1.521 & 2.846 & 2.914 \\
 1 min   & 1.003 & 1.522 & 1.435 & 1.466 \\
 1 h     & 0.895 &       & 1.289 & 1.320 \\
 \hline
 \end{tabular}
\end{table}