\begin{table}%t12
\caption{\label{table:sigblmap_crd}Effect of the coordinate system  on the signal baseline maps.}
 %\centering
\small
 \begin{tabular}{cccccc}
 \hline\hline
 $\tbase$ & Coord. &
 $I$ rms & $Q$ rms & $U$ rms & $P$ rms \\
           & & (nK) & (nK) & (nK) & (nK) \\
 \hline
 1 min   & E & 123.3 & 9.4 & 4.5 & 10.4 \\
 1 min   & G & 115.9 & 6.8 & 7.9 & 10.4 \\
 1 h     & E & 124.0 & 9.4 & 4.6 & 10.5 \\
 1 h     & G & 116.5 & 6.9 & 7.9 & 10.5 \\
 \hline
 \end{tabular}
\end{table}