Institute for Applied Geodesy

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The Institute for Applied Geodesy (IfAG) in Frankfurt am Main was founded around 1950 to carry out the transnational tasks in the German surveying system . In 1997 it was in the newly established Federal Agency for Cartography and Geodesy transferred (BKG).

For almost 50 years the institute researched the solution of practical problems in geodesy , photogrammetry and cartography . In addition to the basic surveying, his tasks also included the publication of the official topographic maps with a scale of 1: 200,000 to 1: 1 million. The IfAG was subordinate to the Federal Ministry of the Interior , carried out special orders from the federal authorities, maintained cooperation with the relevant agencies abroad and edited several series of publications in the three subject areas.

history

After the Second World War , the management of the US occupation army founded the Bamberg "Institute for Earth Surveying " in order to continue the merger of all Central European surveying networks for Germany and Western Europe, which was operated during the National Socialist era . From the eastern regions, the institute continued to have access to the measurement and calculation data that had been collected by the German Army Survey since 1938.

When the final political separation of Europe into an eastern and western part became apparent and the Federal Republic of Germany came into being, the Institute for Applied Geodesy was founded and most of the tasks of the Earth Measurement Institute and many of its specialists were transferred to it. The first tasks of the IfAG included, in particular, further calculations at the ZEN ( Central European Network ) - although in Eastern Europe only with the older data from the years up to around 1943 - and a geoid determination over as large parts of Central and Western Europe as possible.

The publication of topographic maps was only added a little later, when these tasks were transferred from the authorities of the occupying powers to the civil administration. The IfAG soon ceded the tasks of higher geodesy , which were initially barely covered at the universities , to them and to the Bavarian Academy of Sciences and the Munich- based DGFI . The latter was given the designation DGFI Department I, while the Frankfurt offices were run as Department II.

The European network and the Central European geoid

The most important major project of the 1950s comprised the European network and the Central European geoid . Helmut Wolf , who was appointed to the University of Bonn in 1954 , headed the Bamberg Institute and the IfAG agendas for a uniform European network of western European land surveys . Some of the leading scientists came from the top geodetic experts of the Third Reich (see Reichsamt für Landesaufnahme ).

In Bamberg, Helmut Wolf was already working on the calculation of a triangulation network over several countries in Central Europe, despite the depressing consequences of the war destruction , the measurement data of which had been collected in the Berlin Reich Office 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 achieved an accuracy in the meter range (today a few centimeters 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 Wolf, who led this huge task in just four years to complete - with an expected technical situation that seems unimaginable today: To solve the normal equations , which total about 2,000 unknown of arranged as a frame network survey points included, 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.

The European network was continuously improved in the following years and decades, supplemented with new measurement methods and used to test new theories . Today, as ETRS or ETRF, it represents the European part of the world network of satellite triangulation and the most important basis for investigations of terrestrial geodynamics . Research tasks for the definition of reference systems and the ever more precise parameters of the mean earth ellipsoid and the earth's gravity field (see also geoid determination ) are Consequences and goals of the European network and its derivatives.

Topography and cartography

In the course of the 1950s and 1960s, the publication of small-scale topographic maps became the most important economic and personnel task of the IfAG . On behalf of other institutions, thematic maps of geoscientific fields have also been produced and published in some cases .

While the state survey offices were soon responsible for larger-scale topographical maps , the IfAG was left with the production and continuation of the German map series in the scales of 1: 200,000 to 1: 1,000,000, as well as some of the aviation and other special maps. The Standing Committee for Geographical Names (StAGN) also had its office at IfAG, and from around 1985 the transnational agendas of the developing geographic information systems were added. In the field of international contacts, among other things, cooperations in EU projects, EuGeoGIS and conferences such as GeoLIS and AGIT should be mentioned.

Central and Western European geoid

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Later projects