Abstract
Astronomical refraction is calculated on the basis of a numerical integration of differential equations which describe the propagation of a beam of light through a concentrically stratified atmosphere. The calculations make use of the standard atmosphere and the local meteorological conditions at the National Observatory Llano del Hato in Mérida, Venezuela located at an elevation of 3600 m. An interpolation formula is derived which permits a rapid calculation of the refraction, and when compared with other methods shows only minor differences.
