A monograph in astrogeodetic orientation in the current era of satellite positioning technology

Abstract. In recent years, classic surveying astronomy has begun to take interest in published literature. The original authoritative textbooks and manuals on astrogeodetic surveying are perceived to be outdated and obsolete since the advent of satellite positioning and are scarce or impossible to find. Before satellite positioning, surveyors relied on rigorous drawn-out methods of precise astronomical surveying. This recent surge of interest appears to be directed toward astronomical levelling in the determination of the deflection of the vertical in modelling the geoid. Additionally, there has been a spate of literature on astronomic, geodetic, and grid azimuths. An azimuth is a line measured clockwise from the north point. Astronomic azimuth is the line measured in a clockwise direction from the north astronomic pole to a celestial body, and the line pointing to the celestial body forms a great circle through the zenith of the observer, intersecting the observer’s astronomic longitude. The astronomic azimuth is referenced to a local (astronomic) horizon coordinate system perpendicular to the local gravity vector. To illustrate the procedures for astronomical observations, an actual night observation of a star done by the author in May of 1998 was used. This work is intended to show the modern surveyor how field astrometric observations were done before the advent of satellite positioning, and to understand the fundamentals of astrogeodetic methods that has become a lost art and science.