Kinetheodolite

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As cinetheodolite (occasionally also Kinotheodolit ) are great, for the tracked measurement to rapidly moving high goals developed theodolites called.

development

Two ATS helpers , assigned to observe anti-aircraft fire with a Kinetheodolite during World War II .

The first prototypes were made before the Second World War to control air defense and partly as a motorized theodolite . Further developed under the auspices of robotics (see also Erwin Gigas ), they were soon used for precise orbit measurement for the ballistics of high missiles, and occasionally also for earth measurements using stellar triangulation . They received a major development boost a few years before the practical beginning of space travel .

The first kinetheodolite, which is also suitable for precise satellite geodesy, was built at the beginning of the 1950s by the optical-precision engineering company Askania in Berlin, which existed as an independent company until the 1980s. A little later, the Swiss company Contraves , active in the area of ​​drawing machines, followed, some of whose special theodolites are still in use today.

These two best-known instruments allow a precise orbit determination of ballistic missiles (rockets, drop and rocket tests) as well as of balloon probes (weather and other balloon ascents) and of course of artificial earth satellites , by having two observers - each with its own eyepiece - the missile in azimuth or in elevation observe and at the respective measuring thread hold.

The exact registration of the measured angles takes place automatically, as does the associated time measurement (the accuracy of which was already well below the millisecond in 1960 ). Both measuring devices are very solid both in the substructure and in the measuring part (weight over 100 kg), whereby the two observers sit on a common and rotatable, lattice-like device.

Modern applications

A similar but much smaller instrument is (or was) the Moonwatch Apogee , which is, however, designed for use with an observer: the substructure is a theodolite-like, but very massive altazimuth mount, which is about 70 cm long, very bright Telescope carries (free opening about 15 cm, magnification 20x). The partial circles are not in degrees, but in mils (the device was originally developed for the US military), and the observation of the satellites is carried out like a star pass through a vertical network of threads. Since it is practically impossible at angular speeds between 0.1 ° and 3 ° per second, as occurs with satellites close to the earth, as an individual observer to aim precisely in the thread network, the deviation is direct on a 5 'or 10' scale measured in the field of view and added to or subtracted from the elevation angle read.

Both the Apogee and the Kinetheodolite were marginalized in the course of technical developments starting around 1965 and largely decommissioned around 1975. The very labor-intensive measurements, which played a major role in particular for passage measurements in twilight that can hardly be photographed or of very fast reentry phenomena, are now carried out partly by radio location methods and partly by satellite cameras converted to CCD .

In this connection with difficult-to-observe missiles, research projects also arose to record space debris , which today is likely to include many hundreds of "dead" satellites and well over 5,000 other orbiting bodies or components over 10 cm in size. Special search programs that started at the time with Kinetheodolites or in the Moonwatch and Apogee programs by NASA and Smithsonian Astrophysical Observatory (SAO) were further developed for CCD cameras from 1995 , among others at the TU Vienna , the University of Bern , at the German DLR and at some research institutes in the USA and Russia.

See also

literature

  • Fritz Deumlich , Rudolf Staiger: Instrument science of measurement technology. 9., completely reworked and extended Edition. Wichmann, Heidelberg 2002, ISBN 3-87907-305-8 , p. 204: Kinotheodolit .
  • Gerhard HR Reisig: Rocket Research in Germany. How humans conquered space. With a foreword by Lothar Otto. Wissenschaft-und-Technik-Verlag, Berlin 1998, ISBN 3-89685-506-9 , pp. 271ff .: Chapter VI.7.2.3.1, Die Kinotheodolit-Meßbasis.
  • Erwin Gigas : Physikalisch-geodätische Messverfahren , 502 S., Dümmler-Verlag, Bonn 1966