Astronomical refraction theoretical formula in mapping function form

This paper has restudied approximate generating function of neutral atmospheric refractive delay mapping function which is given by the literature.On basis of this restudy this article gets a new astronomical refraction theoretical formula, i.e.expression of mapping function form.Numerical calculation shows that the calculated astronomical difference between using this paper's formula and using refraction tables of Pulkovo is very small.Under the condition of zenith distance30° ,the difference between them is less than 0.05 , in the case of zenith distance less than 65°, the difference between them is less than 0.11 , under the condition of zenith distance greater than 65°, the difference between them decreaces.Until negative value appears at zenith distance 75°, but at just this zenith distance, the absolute value of difference between them becomes increasing.It can be seen that in the case of zenith distance less than 75°, the absolute value of difference between them is less than 0.11.It is feasible to use the mapping function form astronomical refraction formula to replace the complex Plkovo refraction table formula.It also can build the atmospheric delay model by making use of astronomical refraction measured values.