Test area of the SAGE survey

Skysurvey 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 atmosphericparameters 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 reductionprocess of the testing field NGC\,6791, including the data reductionof single-exposure image and stacking multi-exposure images, and properties of the final catalogue.