Astronomical Refraction

In this thesis, the atmosphere's affection to the astrometry observation is summarized. We comment the theoretic basis and the compiled means of many atmospheric refraction versions. And we draw a conclusion that it's necessary to actually measure the values of the atmospheric refraction and to establish the atmospheric refraction model. This method must fit four strict conditions. Our instrument can just satisfy the above conditions.In chapter IV, we introduce a method to accurately measure the values of the atmospheric refraction in different directions.In chapter V, we establish a local atmospheric refraction model by use of actual measure data and point out its disadvantages.At last, a plan was brought forward to establish accuracy atmospheric refraction model in different directions. It is based on different locations and different circumstance conditions.