Hellmut Heinrich Schmid

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Hellmut Heinrich Schmid (born September 14, 1914 in Dresden ; † April 27, 1998 ) was Professor of Geodesy and Photogrammetry (1974–1984) at ETH Zurich , where he retired in 1985. In the 1950s he did research at space institutes in the USA .

Focus of his scientific work in Europe

Schmid worked in the field of geodetic measurement technology on the V2 rocket project in Peenemünde (around 1942). After the war until 1959 he was involved in the development of satellite geodesy and laid the theoretical foundations for analytical photogrammetry in matrix calculations (1950s, USA; see also Richard Finsterwalder ). From around 1965 to 1978 he conducted research in the field of high-precision analysis of photographic measurement images . He made further contributions to geodetic compensation calculations , network improvement and block triangulation . Around 1975 work on the optimization of coordinate transformations and the development of spatial intersection methods for analytical photogrammetry appeared .

Hellmut Schmid became best known for his work on the world network of satellite triangulation , which was determined from 1969 to 1973 by simultaneous measurements from 46 ground stations for the special balloon satellite PAGEOS .

World network of satellite geodesy

This work, which was completed in 1973 in international cooperation , was the world's first surveying network that spanned all six continents with 46 mobile observatories . Although the mutual distances were around 4000 km, Schmid achieved an accuracy better than 1: 1 million (around ± 4–6 meters) in the first step, which at that time meant a step up in accuracy by a factor of 10–20 for intercontinental measurements. In the following years, a combination with measurement data from Doppler satellites even achieved ± 3 m.

The world network of satellite geodesy was designed by Schmid himself and used around 15 satellite cameras of the type BC-4 (1: 4/30 cm) in alternating positions . The PAGEOS satellite , a 40 m balloon satellite at an altitude of around 4,000 km, served as a high target . The measuring teams worked for a few weeks at each observatory until around 100 good photo plates were taken - they also had to be taken simultaneously from two neighboring stations. The measurement groups were of international origin. Germany provided several teams, Austria and Switzerland mostly one alternately.

World network and earth figure

With the world network, Hellmut Schmid established the first global, purely geometric earth measurement , which ideally complemented the intercontinental measurement routes that were previously only possible indirectly (via vertical deviations ). An earth ellipsoid inscribed in the 46-point polyhedron was about three times more precise than the next older solution and agrees with today's results within 10 m (i.e. the expected accuracy). In later years Schmid - like the US geodesist Ivan I. Mueller - dealt, among other things, with the problem of analyzing small systematic errors from the measurement data and comparing them with other, including physical, measurement methods.

Hellmut Schmid has published over 100 specialist articles and has edited several textbooks .

Honors

Since 1970 he has been a corresponding member of the Bavarian Academy of Sciences .

Fonts

  • About the model deformations caused by residual errors in mutual orientation. Dissertation. Technical University of Dresden, 1941.
  • A general analytical solution for the task of photogrammetry, image measurement and aerial photography , organ of the German Society for Photogrammetry e. V., 1958, 1957-58, 103-113
  • A general analytical solution to the problem of photogrammetry. Ballistic Research Laboratories, Report No. 1065, USA 1959.
  • with Karl-Rudolf Koch : Error Study for the Determination of the Center of Mass of the Earth from Pageos Observations. ESSA Technical Memorandum CaGSTM7, Rockville, Maryland 1970.
  • with KR Koch: Geodetic Data. American Institute of Physics Handbook. New York 1972.
  • A worldwide Network of Satellite Triangulation. In: Journal of Geophys. Res. USA 1973.
  • The contribution of photogrammetry to the current state of geodesy. Mitt.-Heft 18. Institute of Geodesy and Photogrammetry, ETH Zurich 1975 ( blue series ).
  • A general adjustment algorithm for numerical evaluation in photogrammetry. Mitt.-Heft 22. ETH Zurich 1978.
  • with Siegfried Heggli: Spatial coordinate transformation. A pseudo-linear formulation as an approximate solution for a strict adjustment with a corresponding Fortran program. Mitt.-Heft 23. ETH Zurich 1978.
  • with René Scherrer: From the free to the stored network Appendix I + II: Accumulation ... minimized gaps; Numerical examples. Bulletin 29th ETH Zurich 1980.
  • with R. Conzett, HJ Matthias (Hrsg.): Ingenieurvermessung 80. Volume 1, B9 / 1-B9 / 9, Dümmler, Bonn 1981.

See also

literature

  • Armin Grün : Special issue on the resignation and 70th birthday of Prof. Dr. Dr. hc HH Schmid. Issue 9, Zurich 1985.
  • Karl Rinner : H. Schmid and the PAGEOS world network. Special issue on the resignation and 70th birthday of Prof. Dr. Dr. hc HH Schmid. Issue 9, Zurich 1985, p. 288 ff.
  • Karl-Rudolf Koch: Prof. Dr.-Ing., Dr.-Ing. eh Hellmut H. Schmid †. In: Journal of Surveying . Volume 123. Stuttgart 1998, p. 282.

Web links

personal data
SURNAME Schmid, Hellmut Heinrich
BRIEF DESCRIPTION Swiss geodesic
DATE OF BIRTH September 14, 1914
PLACE OF BIRTH Dresden
DATE OF DEATH April 27, 1998