True North and Direction-Finding for Archaeoastronomy

Establishing true north is usually an important aspect of archaeoastronomic site assessment. In this paper several methods that can be used to establish true north as well as the azimuth of a sightline are considered. These methods include: by magnetic compass, by celestial observation, by GPS/GNSS coordinates, and by LiDAR, satellite and aerial photography. For each of these methods, advantages and limitations are discussed along with a few practical recommendations.