Helmut Wolf (geodesist)

Helmut Wolf (born May 2, 1910 in Werdau ; † June 6, 1994 ) was a German geodesist and professor at the University of Bonn . It is thanks to him that essential steps towards the establishment of a European network , as well as the first transnational geoid determination in Central Europe.

Scientific work

European network and central European geoid

After the Second World War, Wolf - as Erwin Gigas's successor  - headed the Institute for Earth Surveying founded by the US Army in Bamberg , which was later joined with other departments of the former Reich Office for Land Surveying (German Army Surveying ) to form the Institute for Applied Geodesy (IfAG) in Frankfurt. From Bamberg, Helmut Wolf ran the calculation of a triangulation network over several Central European countries, despite the depressing consequences of the war destruction , the measurement data of which had been collected by the Reichsamt für Landesaufnahme during the Nazi era. The coordinates of the first-order surveying network calculated using the Bowie method were published in 1948/1949 as the " Central European Network " (ZEN) with the support of the then US occupying forces. With its technical preparatory work, the ZEN was then the largest national surveying project on European soil. In terms of its importance for geodesy, this framework network came close to the calculation of the Bessel earth ellipsoid , which had been determined 100 years earlier from measurement data from a similarly large area. The ZEN, however, was based on the Hayford ellipsoid preferred by the US .

In the course of this major project, Wolf also calculated a first geoid over large parts of Central Europe . Due to the war-related gaps in the data, it only achieved an accuracy in the meter range (today a few cm are standard), but was an important prerequisite for later geoid projects in Austria ( Josef Lischauer 1952) and the Federal Republic of Germany (see e.g. Siegfried Heitz 1959).

Because of his success in setting up the ZEN and its geoid, Wolf was able to persuade the International Geodesy Association (IAG) to undertake a uniform adjustment of the Western European and (if not incorporated into the Eastern Bloc ) the Central European land surveys. This resolution, already passed in 1948, subsequently led to the ED50 ( geodetic date for the western half of Europe) and the first versions of a precise European network (see also RETrig , REUN and ED79 ). The Munich geodesy professor Max Kneissl was appointed head of the "Permanent Commission" . The creation of the ED50 was entrusted to Wolf, who completed this enormous task in just four years - in a computational situation that seems unimaginable today: To solve the normal equations , which comprised a total of around 2000 unknowns of the measuring points arranged as a frame network , only stood a 4-species punch card machine is available. All other work - in particular the calculation of the coordinates on the ellipsoid - had to be done with simple electromechanical calculating machines and angle function tables in book form.

Appointment to the University of Bonn

The merits of Helmut Wolf brought him in 1954 when he was already on IfAG, a call to a professorship at the University of Bonn a. There he took on a wide range of teaching tasks in adjustment calculation , parts of engineering surveying, astronomical and physical geodesy, despite a poor infrastructure . In the first year he succeeded in increasing the number of chairs, which led to the establishment of the Institute for Theoretical Geodesy on April 30, 1955 . He was its director until his retirement in 1978.

This institute, for which Wolf's position was converted into a full professorial position, developed into the model for similar founding of several other universities and attracted a large number of committed students and young researchers. According to Wolf, “less the metrological-experimental side of geodesy than the computational-analytical evaluation of the results of the surveying operations” should be treated (see Wolf 1971), which is still the institute's concept today.

Expansion of the range of courses

Wolf's large teaching load was from 1957 through teaching mitigated what those about "geodetic Physics and measurement methods " by Erwin Gigas of the most important was; In 1966, Gigas published a highly regarded textbook on this. He headed the Frankfurt Institute for Applied Geodesy (IfAG) in Frankfurt, a kind of academy institute as the successor to the Bamberg Institute for Earth Measurement .
The gravimetry took over in research and teaching Manfred Bonatz that a new gravimeter to registration and calibration station in the basement Institute and later in tunnels to geodynamic analysis and earth tides used. In 1969/1970, 1972 and 1974 the institute carried out expeditions to Spitzbergen , the Kerguelen and Réunion .

In 1970, lecturer Karl-Rudolf Koch was finally able to take over the lectures on earth measurements, geodetic astronomy and statistics , which the TU Clausthal Erik Grafarend won over. He became an adjunct professor and until 1975, when he accepted a call to Munich, supervised the lectures on Stochastic Processes and an Introduction to Geophysics .

Helmut Wolf on the other hand endeavored from the beginning to renew the mathematical basis of the adjustment calculation and to take the emerging matrix calculation into account appropriately. Wolf also taught balancing when he retired in 1978 and Karl-Rudolf Koch became his successor. He continued to conduct research in the field of 2- and 3- dimensional networks, the Doppler satellite networks , the hypothesis tests and the L1 norm estimates. In his retirement he published the newly developed Helmert Wolf - block adjustment , the special covariance matrices ensures the best possible accuracy of networked measurement blocks.

Appreciation

Wolf died in the middle of 1994. In January 1995 a prominent memorial colloquium was held at the Bonn institute to honor him .

The importance of Helmut Wolf for international geodesy can be explained. a. judge from the fact that his work is cited in the 5th volume of the Handbook for Surveying (Earth Measurement) in 20 different places. At least four institutes for theoretical geodesy were established by 1980 , some of them based on the Bonn model. Wolf published around 200 specialist articles, only a small part of which can be seen on the Internet.
Helmut Wolf is certainly one of the 10 most important scientists who founded the progress of international geodesy in the middle of the 20th century. In 1975 Wolf was awarded the Helmert commemorative coin from the German Association for Surveying . Since 1968 he has been a corresponding member of the Bavarian Academy of Sciences and since 1977 of the Braunschweig Scientific Society .

literature

• Walter Großmann : Geodetic calculations and images in the national survey . 3. Edition. Konrad Wittwer, Stuttgart 1976 (cited p. 225).
• Karl Ledersteger : Astronomical and physical geodesy (earth measurement) . In: Handbuch der Vermessungskunde (JEK), Volume VJB Metzler, Stuttgart 1968 (quotations from Helmut Wolf in around 20 sections).
• Helmut Wolf: The Institute for Theoretical Geodesy. In: 150 Years of the Rheinische Friedrich-Wilhelms-Universität zu Bonn 1818–1968 , Agricultural Sciences , Bouvier-Röhrscheid, Bonn 1971, p. 174ff.

Web links

• Literature by and about Helmut Wolf in the catalog of the German National Library
• The development of the Bonn institute since 1954/55
• The Wolf formulas for the Helmert-Wolf blocking (HWB)
• 50 years of the Institute for Theoretical Geodesy (University of Bonn, 2005)