\begin{table}%t2
%\centering
\par
   \caption{Kernel parameters for both the $V$ and $R$ bands.}
   \label{para}
   \begin{tabular}{lcc}
\hline\hline
 & $V$ band & $R$ band \\
\hline
Kernel size    & $27 \times 27$ pixels       & $27 \times 27$ pixels       \\
Number of Gaussians      & 3     & 3   \\
Respective sigmas of the Gaussians   & 1.2, 2.8, 5.2 pixels & 1.1, 2.8, 5.4 pixels \\
Degree of the 2D apodization polynomials       & 4, 4, 4      & 6, 3, 2              \\
Degree of the 2D polynomial enabling space-variation of kernel model's coefficients & 1  & 1 \\
Degree of the 2D polynomial describing the space variations of the sky background   & 1  & 1  \\
Number of stamps selected in the images for the kernel fit   & $3 \times 3$  & $3 \times 3$   \\
Stamp size     & $45 \times 45$ pixels  & $45 \times 45$ pixels       \\
\hline
   \end{tabular}
\end{table}