Computer Program for Horizontal Circle Astronomy

Any astronomical observation taken on the horizontal circle of a theodolite may be represented by an equation in three unknowns, latitude, longitude, and azimuth. In practice, observations are usually made to determine only one specific unknown. Such an observation represents a special case of the general equation. By inserting zeros into the general matrix of the normal equations, all special cases can be covered. A single computer program based on the general theory can be used as a universal solution to all types of observations made on the horizontal circle. The same program calculates the variance-covariance matrix from which the mean square errors of the unknowns is obtained. Complete details of the basic theory and computer program are given.