Circular location

The articles telescope position and circular position thematically overlap. Help me to better differentiate or merge the articles (→  instructions ) . To do this, take part in the relevant redundancy discussion . Please remove this module only after the redundancy has been completely processed and do not forget to include the relevant entry on the redundancy discussion page{{ Done | 1 = ~~~~}}to mark. Acky69 ( discussion ) 18:18, Aug 13, 2020 (CEST)

Fennel theodolite around 1900 (Zeiss Museum Oberkochen). On the right in the picture the vertical circle.

The position of the vertical circle to the left or right of the observer is called the position of a theodolite or a transit instrument .

The shown theodolite from the turn of the century is in a circle on the left (from the perspective of an observer standing behind the instrument ). If you were to break through the telescope , i.e. turn it upwards by at least 90 °, it would be in a circle on the right (for the viewer who then stands behind the instrument) .

The measurement in both circular positions, which can be used to eliminate several instrument errors (especially height index and target axis errors ), is carried out by rotating the measuring instrument by 180 ° around the vertical axis and breaking through the telescope. The two readings of the height or zenith angle on the vertical circle then add up to 360 ° or 400 gon if the instrument is  correctly adjusted .

literature

• Heribert Kahmen, Surveying , Chapter 3, Theodolite and the measurement of directions and angles. 20th edition, 680p., De Gruyter-Verlag 2005