Karl-Rudolf Koch

Karl-Rudolf Koch (born July 30, 1935 in Hilchenbach , Siegen district) is a German geodesist and professor at the University of Bonn . He has been retired since July 2000 ; Wolf-Dieter Schuh from Graz University of Technology was appointed as his successor .

He is best known in specialist circles for his scientific contributions to compensation calculations and satellite geodesy . Since around 1980 he has held numerous honors and several honorary doctorates (including Stuttgart 1999).

biography

Karl-Rudolf Koch studied geodesy at the University of Bonn and then worked as a surveying referendar and university assistant in Bonn. After receiving his doctorate in 1965 and his habilitation in 1967, he received a research position in the USA : first at Ohio State University in Columbus, then at the National Geodetic Survey (NGS) in Rockville, Maryland. At the NGS, where they worked on various satellite technologies , Koch worked again and again until 1983.

In 1970 he returned to Bonn from the USA as an associate professor for physical geodesy and in 1978 became director ( full professor ) of the Institute for Theoretical Geodesy as the successor to the institute's founder, Helmut Wolf . The new agendas of Koch included - unlike at similar institutes e.g. B. in Austria or southern Germany usual - also teaching tasks in the adjustment calculation and statistics . This activity should fascinate him for a long time and make him the inventor of some innovative methods.

The German Geodetic Commission (DGK) accepted him as a full member in 1979 , as did the ESA for the radar altimeter project group , where he worked as a consultant until 1987. During this time he temporarily went to America and Asia ( Curitiba / Brazil, Calgary, Haifa and Wuhan ) as a visiting professor . At ESA, 1989–1993, following his work in altimetry , he coordinated the evaluation of the altimeter data from the geodetic and remote sensing satellite European Remote Sensing Satellite .

Koch took on a major task from 1987 to 1997 as director of the German Geodetic Research Institute (DGFI) with its two departments in Munich (DGFI I., from which Christoph Reigber and Harald Schuh emerged ), and the former Institute for Applied Geodesy (IfAG) in Frankfurt am Main . Especially in satellite geodesy, Koch was able to secure a top position for his work group in global geodetic research.

In addition to the organizer, the scientist Koch at the University of Bonn gradually became a pioneer in the areas of adjustment calculation and applied statistics: When research on the methods of parameter estimation stagnated around 1975 , he was able to establish a reference to mathematical statistics with his work . Experts see what he contributed to semantic modeling as a “ quantum leap ” in modern geodesy - and also in geoinformatics , which is increasingly dealing with problems of data quality .

Main research topics

As a result of Koch's scientific successes, which he made known through repeated participation in seminars and international research projects , the Institute for Theoretical Geodesy , which he continued to run, became a Bonn “pilgrimage” for researchers from all over the world. Among geodesists, it is one of the leading German institutes for higher geodesy - alongside the institutes in Hanover and Munich (which are active in other areas of earth measurement ) . Koch has also done fundamental things in the field of digital signal processing and, together with his long-time colleague Michael Schmidt, wrote the textbook "Deterministic and stochastic signals with applications in digital image processing".

Koch worked most intensively on the subject of potential theory and earth's gravity field . In 1969 he formulated the geodetic boundary value problem for a known earth surface; In 1972 he and AJ Pope were able to prove the existence and uniqueness of the solution. His institute colleague Erik Grafarend added the free boundary value problems and the oblique boundary value problem to this research. 1969–1971, Koch was stimulated by current questions of geometric and dynamic satellite geodesy to potential-theoretical solutions that enabled a gravity field determination from measurements from optical satellite cameras and Doppler satellites with additionally introduced gravity anomalies .

In this context, he made his well wesentlichster contribution to geoid determination , which he in the 1970s under the term potential of the simple layer (ger .: simple layer potential developed); The first publications on this were made between 1969 and 1971 together with Foster Morrison and Bertold U. Witte . Koch came across this method of thin surface coverings when satellite geodesy began to suffer from the increasing flood of data from measurements of the orbits and the computers could not keep up, so to speak. In this way, the Bonn researchers were able to supplement the previously predominant method of developing the spherical function of the gravitational potential ("harmonic coefficients", see also mass functions ) with a very effective, robust calculation method, albeit discontinuous at the model edges.

In a nutshell: With Koch's method, you no longer need lengthy days of calculation to calculate 50,000 mass functions of the earth's body from 100,000 data , but could start directly on so-called surface occupations at the points of the greatest gravity anomalies. This “occupation” of the earth's surface with fictitious , thin masses is, in addition to its computational efficiency, also very flexible , because it does not require a geometrically rigid grid when modeling the earth's gravity field. A few years later, the first precise measurement data from satellite altimetry was also incorporated into improved earth models using the same flexible approaches .

Not least because of this innovative method of satellite geodesy, which made both the geoid determination and the difficult celestial mechanics of near-earth space probes solvable “before their time”, Koch received a call in 1972 from the Vienna University of Technology, which is leading in geoid research and (geo) physical geodesy . However, after lengthy negotiations, Koch did not succeed the Viennese professor Karl Ledersteger , who died suddenly , because Bonn was able to offer him better financial conditions.

Web links and sources

• Literature by and about Karl-Rudolf Koch in the catalog of the German National Library
• on the history of the institute in Bonn
• 50 years of the Institute for Theoretical Geodesy, University of Bonn 2005 (PDF file; 1.42 MB)

Individual evidence

1. ↑ Karl-Rudolf Koch, Michael Schmidt: Deterministic and stochastic signals: with applications in digital image processing . Dümmler, Bonn 1994, ISBN 3-427-78911-X .
2. ^ KR Koch, AJ Pope: Uniqueness and existence for the geodetic boundary value problem using the known surface of the earth . In: Bulletin Géodésique . tape 106 , 1972, pp. 467-476 , doi : 10.1007 / BF02522053 .