\begin{table}%t2
\caption{Systemic spectrometer velocities used at different Galactic longitudes to optimise available velocity bandpass. These were chosen from visual inspection of the longitude-velocity maps of \citet{dame2001}.}
\label{tbl:central_vlsr}
%\centering
\small
\begin{tabular}{lc}
\hline
\hline
Gal. longitude& Centred velocity (\kms)\\
\hline
180--270& 50 \\
271--300& 20 \\
301--320& --10 \\ 
321--330& --40\\
331--350& --75\\
\hline
\end{tabular}
\end{table}