Determination of Look Angles to Geostationary Communication Satellites

Abstract

Basic geodetic theory is applied to determine the geodetic azimuth and geodetic altitude required to point dish antennas to geostationary communication satellites. The mathematical treatment presented here takes into consideration the ellipticity of the earth. This generalization contrasts with standard formulas published in technical books in satellite communication engineering where a spherical approximation is implemented. Comparisons between the spherical and more rigorous ellipsoidal methods are discussed. Although the differences between the two approaches are not significant, they should be taken into consideration when very precise pointing to geostationary communication satellites or other space objects is dictated. The suggested method is simple to understand and straightforward to implement, and due to its advantages should replace any spherical alternative currently in use.