\begin{table}%t2
\caption{\label{ISO-obs}Format of ISOGAL observations Table (version 1) -- 384 entries
(see examples in Table~\ref{ISO-obs_ex}).}
%\centerline
{\begin{tabular}{rllll} 
\hline\hline
Col. & Name & Format & Units [range] & Description \\
\hline
 1 & ION       & a8   &                  & ISO Observation number  \\
 2 & name      & a13  &                  & ISOGAL observation name \\
 3 & date      & a6   & YYMMDD	         & date of observation \\
 4 & j\_day    & i4   &                  & Julian day of observation - 2~450~000\\
 5 & qual      & i1   & [1,2]            & quality of image$^a$\\
 6 & $l$\_off    & f5.1 & arcsec           & applied offset in Galactic
longitude$^b$\\
 7 & $b$\_off    & f5.1 & arcsec           & applied offset in Galactic latitude \\
 8 & G\_lon    & f8.4 & deg [$-180$--+180] & Galactic longitude of raster centre \\
 9 & G\_lat    & f8.4 & deg [$-90$--+90]   & Galactic latitude of raster centre \\
10 & $dl$        & f6.4 & deg	   & half width of raster in longitude \\
11 & $db$        & f6.4 & deg	   & half width of raster in latitude\\
12 & RA        & f8.4 & deg              & RA (J2000) of raster centre \\
13 & DEC       & f8.4 & deg              & Dec (J2000) of raster centre \\
14 & filt      & i1   & [2,3,5,6,9]      & LW filter number  \\
15 & pfov      & i1   & arcsec [3,6]     & pixel field of view \\
16 &~mag\_lim  & f5.2 &~mag              & ISO~magnitude cutoff$^c$ \\
17 & nb\_sour  & i4   &                  & number of extracted sources brighter
than~mag\_lim \\
18 & rot       & i1   & [0,1]            & applied transformation (270$^{\circ}$
rotation) to the raster$^d$ \\
19 & $x$\_inv    & i1   & [0,1]            & applied transformation ($x$-inversion)
to the raster \\
20 & $y$\_inv    & i1   & [0,1]            & applied transformation ($y$-inversion)
to the raster \\
21 & $m$         & i2   &                  & number of raster steps in $x$ in final raster \\
22 & $n$         & i2   &                  & number of raster steps in $y$ in final raster \\
23 & $dm$        & i3   & arcsec           & size of step between $x$ (final) raster positions \\
24 & $dn$        & i3   & arcsec           & size of step between $y$ (final) raster positions \\
25 & angle     & f6.2 & deg              & angle from the upward axis to the north
in the final raster \\
26 & $NX$        & i3   & pixel            & number of pixels in $x$ of final raster \\
27 & $NY$        & i3   & pixel            & number of pixels in $y$ of final raster \\
\hline
\end{tabular}}
\smallskip
$^a$~{Image
quality: 1 is standard quality, 2~is medium quality (in most cases, the problem
is that the first individual image of the raster appears brighter than the other
ones). Images of bad quality have not been used to build the catalogue.}\\
$^b$~{The astrometry of the published raster images has been
corrected to match the DENIS astrometry if any (see Sect.~\ref{new-images}).
The offset values given in this table have been added to the initial raster
coordinates.}\\
$^c$~{The ISO
magnitude cutoff has been computed for each observation to correspond at least
approximately to a $50$\% completeness level (see Sect.~\ref{artif}).}\\
$^d$~{Columns 18--20: all the published images
are oriented with $l$ along decreasing~$x$ and~$b$ along increasing~$y$. In each
column, a 1~means that the corresponding transformation has been applied to the
initial (OLP7 processed) raster, and a~0 means that this transformation was not
needed.}
\end{table}