Starlight atmospheric refraction model for a continuous range of height

The new starlight atmospheric refraction model, given by empirical formula within the continuous range of height from 20 to 50 km in the stratosphere, has taken into account all the factors affecting starlight atmospheric refraction, including atmospheric density, temperature and density elevation. Atmospheric pressure decreases as height increases and its gradient also decreases when the height increases so the atmospheric pressure variation with height can be modeled as an exponent distribution P(h) = a · exp(bh). The temperature is almost independent of the ground in the range of height from 20 to 50 km, but this variation is not uniform and in the upper air, the temperature gradient is high due to absorption of ultraviolet radiation by ozone. The starlight refraction angle at tangent height of 25 km calculated by the new model is 147.8 arcsec, which has an error of 0.2 arcsec compared with the observed data.