Hellmut Schmid

Hellmut Heinrich Schmid ( born September 14, 1914 in Dresden, † 27 April 1998) was a professor of Geodesy and Photogrammetry ( 1974-1984 ) at the ETH Zurich, where he became Professor Emeritus in 1985. In the 1950s, he conducted research on aerospace institutes of the United States.

The focus of his scientific work in Europe

Schmid worked in the field of geodetic measurement technique when V2 rocket project at Peenemunde ( around 1942 ). After the war until 1959, he played a part in the development of satellite geodesy and laid the theoretical foundations for the Analytical Photogrammetry in Matrix ( 1950, USA; see also Richard Finsterwalder ). From about 1965 to 1978, he conducted research in the field of high-precision evaluation of photographic measurement images. Other contributions he made to the geodetic compensation calculation, grid improvement and Blocktriangulation. Around 1975 published work on the optimization of coordinate transformations and the development of spatial intersection method for analytical photogrammetry.

Best known Hellmut Schmid was his participation in the global network of satellite triangulation, which was from 1969 to 1973 determined by simultaneous measurements of 46 ground stations for special balloon satellite Pageos.

World Network of Satellite Geodesy

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

The World Network of Satellite Geodesy was designed by Schmid himself, and used in alternating -up about 15 satellite cameras of type BC -4 ( 1:4 / 30 cm). As a wedding destination served the specially satellite launched PAGEOS, a 40 m large balloon satellite to approximately 4000 km altitude. The survey teams a few weeks per Observatory were each active until around 100 good photographic plates were taken - they had to succeed simultaneously by two neighboring stations. The measurement groups were of international origin. Germany provided several teams, Austria and Switzerland usually a turn.

World power and figure of the earth

With the World Network Hellmut Schmid established the first global, purely geometric geodesy, which complemented the hitherto possible only indirectly (via deflections of the vertical ) measurement intercontinental routes ideal. One of the 46 -point polyhedron inscribed Erdellipsoid was about three times more accurate than the next older solution and is consistent with the present results within 10 m (ie, the expected accuracy ) match. In later years, Schmid addressed - as well as the US- surveyor Ivan I. Mueller - among others, the problem of analyzing small systematic errors from the measurement data and with others, including physical, align measurement methods.

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

Writings

  • Of the model deformation caused by the residual error of the mutual orientation. Dissertation. Technical University of Dresden, 1941.
  • A general analytical solution to the problem- of photogrammetry. Ballistic Research Laboratories, Report No.. 1065, USA 1959.
  • Karl- Rudolf Koch: Error Study for the Determination of the Center of Mass of the Earth from Observations Pageos. ESSA Technical Memorandum CaGSTM7, Rockville, Maryland, 1970.
  • With K. 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 present state of geodesy. Mitt booklet Institute of Geodesy and Photogrammetry 18, ETH Zurich, 1975 ( blue series ).
  • A general Stabilization algorithm for the numerical evaluation in photogrammetry. Mitt booklet 22 ETH Zurich in 1978.
  • Siegfried Heggli: Spatial coordinate transformation. A pseudo- linear formulation as an approximation solution for a strict adjustment with corresponding Fortran program. Mitt booklet 23 ETH Zurich in 1978.
  • With René Scherrer: From free to the stored power Annex I II: Anfelderung ... minimalized misclosures; Numerical examples. Mitt booklet 29 ETH Zurich in 1980.
  • With R. Conzett, Matthias HJ (ed.): Engineering Surveying 80 Volume 1, B9/1-B9/9, Dümmler, Bonn 1981.
April 27 V-2 rocket Transformation (function) Vertical deflection Reference ellipsoid Scientific literature Karl-Rudolf Koch Ohio State University
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