\begin{table}%t7
%\centering
\small
\caption{Absolute value of the noise cross-power-spectrum for the
145~GHz detectors, averaged in the 0.1--2~Hz range. The numerical
values have been normalized to the noise auto-power-spectrum of
detector 145W1, which is $1.2 \times 10^{-6} V^2/\rm Hz$ at the ADC
input.
\label{tab:noise_x}}
\begin{tabular}{ccccccccc}
\hline\hline 
~  &  W1      &    W2    &   X1     &    X2    &    Y1    &    Y2    &    Z1    &    Z2    \\
\hline 
W1 &  1.000   &  ~       &    ~     &     ~    &     ~    &     ~    &     ~    &     ~    \\
W2 &  0.060   &  0.850   &    ~     &     ~    &     ~    &     ~    &     ~    &     ~    \\
X1 &  0.034   &  0.031   &  1.100   &     ~    &     ~    &     ~    &     ~    &     ~    \\
X2 &  0.033   &  0.031   &  0.059   &  1.000   &     ~    &     ~    &     ~    &     ~    \\
Y1 &  0.048   &  0.040   &  0.035   &  0.035   &   1.200  &     ~    &     ~    &     ~    \\
Y2 &  0.043   &  0.036   &  0.035   &  0.035   &   0.016  &  1.200   &     ~    &     ~    \\
Z1 &  0.037   &  0.033   &  0.038   &  0.037   &   0.041  &  0.041   &  1.500   &     ~    \\
Z2 &  0.060   &  0.054   &  0.063   &  0.061   &   0.066  &  0.066   &  0.096   &   4.300  \\
\hline
\end{tabular}
\end{table}