Design of a System of Producing Photometric Reference Images for Image Subtraction for AST3

The Three Antarctic Schmidt Telescopes(AST3)will be installed at the South-Pole Kunlun Station located at the Antarctic Dome A.One purpose of AST3 is to search for variable objects by the method of image subtraction.The first step of image subtraction is to produce a photometric reference image.Images obtained from follow-up long-time observations are subtracted by corresponding reference images,which can make the variable objects stand out. Reference images play important roles in image subtraction.This paper describes an elaborated production process of reference images and validates its effectiveness.