Direction transmission

In geodesy, direction transfer is the transfer of a precisely oriented direction from a survey point to a nearby second point. It can be done in several ways, such as

• by autocollimation of the two measuring telescopes (only for distances of a few meters)
• through suitable alignment (alignment in a straight line) or a distant mire
• by aiming at a very distant long-term goal
• or astronomically by simultaneous measurement of a star

where the two aiming rays are de facto parallel in the 4th method .

The most accurate method is the simultaneous observation of a star :

• at night of a (not too bright) fixed star
• during the day e.g. B. of the sun, moon or Venus.