Testing Area of the SAGE Survey
  Sky survey is one of the most important motivations to improve the
astrophysics development, especially when using new photometric bands. We are
performing the SAGE (Stellar Abundance and Galactic Evolution) survey with a
self-designed SAGE photometric system, which is composed of eight photometric
bands. The project mainly aims to study the stellar atmospheric parameters of
$\sim$0.5 billion stars in the $\sim12,000$ deg$^2$ of the northern sky, which
mainly focuses on the Galactic sciences, as well as some extragalactic
sciences. This work introduces the detailed data reduction process of the
testing field NGC\,6791, including the data reduction of single-exposure image
and stacking multi-exposure images, and properties of the final catalogue.
