\begin{table}%t2
%%\centering
\par
\caption{SPI instrument characteristics.} 
\label{characteristics}
\begin{tabular}{ll}
\noalign{\smallskip}
\hline
\hline
\noalign{\smallskip}
Energy range              & 20~keV--8 MeV \\
Energy resolution         & 2.5~keV at 1.33 MeV \\
Angular resolution        & 2.5\deg \\
Positioning accuracy      & 10 arc min  \\
Fully Coded Field-of-view & 16\deg  \\
Timing                    & $\pm$ 52 $\mu$s \\
Detector area             & 500 cm$^2$ \\
Detector thickness        & 7 cm  \\
Total weight              & 1228 kg  \\
\noalign{\smallskip}
\hline
\end{tabular}
\end{table}