Mire
![](https://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Mire%2CPfeiler%2CChronograf%2C34%C2%B204_-_zugeschnitten.jpg/330px-Mire%2CPfeiler%2CChronograf%2C34%C2%B204_-_zugeschnitten.jpg)
A mire (cf. Latin mirus or (fem.) Mira "striking") is a system of two or more target marks with which an exact reference direction, e.g. B. the north-south direction is defined for astronomical devices or navigation instruments .
The name comes from classical astrometry , which required precise meridian marks in earlier observatories in order to set up the instrument axes in the meridian or east-west direction.
Such marks are used, which are attached between 3 meters and about 100 meters away from the measuring point , depending on the purpose , also today for fixed meridian and passage instruments , as a reference system for first-order surveying pillars or for setting up gyroscopic instruments in navigation . If the distance of the mire is large, it may be sufficient. U. a centered light; A stable collimator telescope is used for short distances (see picture).