Reducing the impact of a vertical refraction by a two-regime model

This paper deals with the creation of a mathematical model to eliminate or reduce the impact of a vertical refraction from the results of repeated trigonometric measurements of elevations. A multiple regression model with air temperature and pressure as the explanatory variables is proposed and subsequently modified into the form of a two-regime model. The threshold parameter is given by the threshold function, which represents an approximation of the relationship between the atmospheric pressure and temperature. An investigation of the quality of the proposed models and the application of the selected model on the experimental measurement results is also performed.