Co-ordinator

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The Koordinatograf or coordinatograph is a table large, manually operated signs machine for mapping geodetic recordings. It was developed in the 19th century and manufactured by some surveying companies until around 1970, including a. by Rudolf & August Rost in Vienna. After that, work technology increasingly switched to electronically controlled devices.

The machine consists of a flat base for the drawing cardboard and a long, solid ruler (abscissa) on which a second ruler (ordinate) is arranged so that it can be moved exactly at right angles. Both rulers carry several finely divided scale scales with vernier and reading magnifiers , the movable ruler also has a measuring head with a mapping needle , which can also be exchanged for drawing instruments or a measuring magnifier . The movement along the rulers is done with a clamping lever and a fine movement .

The scale scales have the most common scales 1: 500, 1: 1000 and (for the classic cadastre ) 1: 2880. T. can also be exchanged for others like 1: 1440 or 1: 2500.

The setting of the coordinate values (either as local or as Gauß-Krüger coordinates x, y) was carried out manually using the magnifying glasses and fine movements, whereby operation by two technicians was also possible. After setting its calculated coordinates, each point was poked into the box with the needle ("pricked out") and given its recording number. After completing this work, the measuring points were checked using the blocking measures ; Alignment was sometimes used for straight lines , and a circular template for arcs .

With careful work, error rates below one percent could be achieved. Additional local dimensions or secondary points (e.g. from eccentrics ) were added manually using a conveyor .

The development of automated mapping began around 1960, and a few years later - u. a. by the punch tape -controlled Coradimat began enforce -. In the course of the 1970s , various large plotters came into use for mapping , although their step size was initially too small for the required accuracy of approx. 0.05 mm. Today the automatic flow of data from the total station via the PC to the drawing machine is almost entirely implemented. The coordinate measuring machines were developed for special measuring purposes .

literature

  • Franz Ackerl: Geodesy and Photogrammetry , Chapter 20. Verlag Georg Fromme, Vienna 1959
  • Heribert Kahmen : Surveyors . De Gruyter textbook, Berlin 1997