\begin{table}%t1
\caption{Characteristics of the data.\label{tab:cali}}
%%%\centerline
\par
{\begin{tabular}{@{}rccrccrcc}
\hline\hline
Date &Telescope&Instrument&FOV&Pixel scale&Exp. time& $\sigma_{K}$ &${\rm seeing}$ &$\mu_{K,\rm lim}$\\
(1)  & (2)     &   (3)    & (4) & (5)           & (6) & (7) & (8)  & (9) \\
\hline
29 Sep. 96 &4.2~m WHT&WHIRCAM&$\sim$$1\arcmin\times1\arcmin$&0.240$\arcsec$/pixel&900~s&0.03 &0.8$\arcsec$ &21.8 \\
14 Oct. 97 &3.5~m CAHA&OMEGA&$\sim$$6\arcmin\times6\arcmin$&0.396$\arcsec$/pixel&1800~s&0.06 &1.2$\arcsec$ &20.9 \\
15 Oct. 97 &3.5~m CAHA&OMEGA&$\sim$$6\arcmin\times6\arcmin$&0.396$\arcsec$/pixel&1800~s&0.16 &1.1$\arcsec$ &20.9 \\
16 Oct. 97 &3.5~m CAHA&OMEGA&$\sim$$6\arcmin\times6\arcmin$&0.396$\arcsec$/pixel&1800~s&0.12 &0.9$\arcsec$ &20.9 \\
3 Feb. 99  &3.5~m CAHA&OMEGA&$\sim$$6\arcmin\times6\arcmin$&0.396$\arcsec$/pixel&2700~s&0.09 &1.3$\arcsec$ &21.0 \\
\hline
\end{tabular}}
\smallskip
\par
(1) Observing date. (2) Observing telescope. (3) NIR instrument used. (4) Field of view of the images. (5) Pixel scale. (6)~Exposure time used in the science exposures. (7) Photometric error derived from the standard deviation around the mean photometric zero-point per night. (8) Mean $FWHM$ of field stars on the images along each night. (9) Mean~3$\sigma$ limiting surface brightness magnitude of the science exposures for each~night.
\end{table}