The determination of the astronomical azimuth of a line is not a difficult task for surveyors any more.
The aim of this paper is to analyze the theoretical details and errors in order to propose the use of
ordinary total stations, for an easy, efficient and accurate determination of the astronomical azimuth of
a line by the hour angle method via Polaris sightings. As many modern total stations have a built – in
quartz clock they can register automatically the UTC time as well as the angle measurements
(horizontal and zenith) of each observation. The total fieldwork time needed is about 10 minutes and the
accuracy that may be achieved is about ± 2″. This procedure will be proven to be easier than the
determination of the geodetic azimuth of the same line. The calculation is independent and the result is
free of the errors that the coordinates of a survey mark may contain, because they are not used.
However good positional data is required from other sources. Astronomical azimuths are an alternative
solution for the surveyors in order to check or orient their field surveys and arbitrary networks
independent of the GPS system.