Tower height determination

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With tower height determination are measuring method referred to, in which the oblique or horizontal distance can not be measured at the high point. There are two ways to determine the route to the high point indirectly via angle measurements .

Determination of tower height with a horizontal auxiliary triangle

This method is also called the baseline method. The two directions and vertical angles to the high point are measured from two points of view . The measured horizontal distance ( base line ) between the points of view and the respective angles from this base to the high point define the horizontal auxiliary triangle , which can be resolved by means of the law of sine for the desired horizontal distances to the high point. With the help of these horizontal lines and the zenith angle, which is determined at the respective point of view to the high point, the height difference between the point of view and high point can be calculated in a right-angled (vertical) triangle . With the help of the station height and the calculated height difference, the height of the high point is determined. By calculating the point height from both points of view, a measurement and calculation control is given. The base should be placed as close as possible to the high point and the horizontal auxiliary triangle should be roughly isosceles.

Determination of tower height with a vertical auxiliary triangle

This method is sometimes called the baseline method (hardly documented, see). Here, the high point and two points of view in a vertical must level after another in an escape lie. The horizontal distance between the points of view is measured, as are the two zenith angles to the high point. There are two right-angled (vertical) triangles with which the height difference between the points of view (first unknown) and the high point can be determined, provided that the horizontal distance between the high point and the closest point of view (second unknown) is known. It can be calculated by equating and eliminating the height difference.

With the now known horizontal distance and the zenith angle measured at the respective standpoint, the height difference between the standpoint and the high point is calculated in a right-angled triangle. The height of the position (including the height of the instrument of the theodolite) must be added to this height difference . This method is used in particular when there is not enough space for a horizontal auxiliary triangle (e.g. in localities).

See also

Web links

Individual evidence

  1. ↑ http://tu-dresden.de/die_tu_dresden/fakultaeten/fakultaet_forst_geo_und_hydrowwissenschaften/fachrichtung_geowwissenschaften/gi/ig/lehrveranstaltungen/wasserwirtschaft/wasserwirtschaft/turmuebung.pdf
  2. ↑ This designation is not used in the specialist literature, see e.g. B. Franz Ackerl "Geodesy" Part I , pp. 293-298, Verlag G. Fromme, Vienna 1950