Simple Methods for Calculating the Azimuthal Coverage of HF Directional Antennas

摘要

Methods of calculating the azimuthal coverage of HF directional antennas are described and worked examples are given. Particular attention is paid to spherical trigonometry formulas employing auxiliary quantities because of their suitability for use with simple hand-held electronic calculators. The relationships between sides and angles of oblique spherical triangles, collated from several sources, are listed and the value of applying tests based on these relationships prior to making detailed solutions of spherical triangle problems is demonstrated. (Author)