Prof. Dr. Walter Dieminger passed away on 29th September 2000 at the age of 93.Born in Würzburg, he received his scientific education at the Technische Hochschule München, graduating in 1931 with a diploma in physics. In 1935 he obtained the degree Dr. rer. techn. with a thesis on the dependence of radio wave propagation on the properties of the ionosphere, under the supervision of Jonathan Zenneck. His first professional position was with the Deutsche Versuchsanstalt für Luftfahrt, where he was involved in the development of radio navigation methods. In addition he acquired the title Flugbaumeister after a state examination and also got a pilot's licence. He established a scientific team for radio wave propagation studies which developed into the Zentralstelle für Funkberatung, to which he was appointed director in 1943. This agency with a staff of about 300, provided short wave radio propagation forecasts for the German military. It was first based in Rechlin (north of Berlin) and later in Leobersdorf/Austria and ran ionospheric observatories distributed over the whole Europe between 35-70 N and 15 W – 30 E.

Since Dieminger's team was very successful in their radio propagation forecasts and their scientific studies on the ionosphere, their work was regarded as important for the Allies, and they became a 'target' of the Field Intelligence Agency Technical (FIAT) after the end of the war. As a result the Royal Air Force moved a skeleton staff and their equipment into the British Zone of post-war Germany to Lindau near Göttingen. A very essential and beneficial role in this transfer was played by the well-known ionospheric scientist William Roy Piggott, a student of Sir Edward Appleton who served as a technical officer at that time. Dieminger and Piggott enjoyed a sincere friendship stretching back to these days.

Beginning in 1946 Dieminger established a ionospheric research institute in Lindau, first under the administration of the Kaiser-Wilhelm-Gesellschaft, which was succeeded by the Max-Planck-Gesellschaft. Dieminger was one of the signatories of the founding protocol of this scientific society on 26th of February 1948. The institute developed gradually into the Max-Planck-Institut für Aeronomie, in 1951 it was incorporated in the Max-Planck-Gesellschaft of which Dieminger became a scientific member. The scientific activities under his director- and leadership comprised upper atmospheric and ionospheric research and radio wave propagation studies. Among his special interests were sub-polar and trans-equatorial radio wave propagation. For these studies Dieminger established close collaborations with Finnish ionospheric observatories, in particular with the Geophysical Observatory in Sodankylä, and set up anionospheric observatory in Tsumeb (today in Namibia). The latter was also a German contribution to the International Geophysical Year (IGY, 1957-59). In the following years he and his institute participated in various scientific campaigns like the International Quiet Sun Year (IQSY) and in scientific activities of COSPAR and ESRO. He also established close contacts and collaborations with several foreign geophysical institutes.

Diemingers academic career continued with the Habilitation (on ground backscatter of ionosperically reflected radio waves) at the Universität Göttingen in 1948. He was appointed an außerplanmäßiger Professor in 1954 at this university. In appreciation of his scientific achievements he became a member of the Finish Academy of Sciences in 1959, a corresponding member of the International Academy of Astronautics in 1965, a member of the renowned Akademie der Naturforscher Leopoldina zu Halle in 1968, and a member of the Österreichische Akademie der Wissenschaften. He also received the Karl-Friedrich-Gauss medal in 1971. His local and national contributions to science and scientific institutions were also honoured with the Honorary Citizenship of Katlenbug-Lindau in 1975 and the Bundesverdienstkreuz am Bande (Cross of Merits of Germany) in 1972.

Very early in his scientific career Dieminger became associated with the Union Radio-Scientifique Internationale (URSI) and participated in its activities. Already in 1938 he was a member of the German delegation to the URSI General Assembly in Italy. From 1954 to 1967 he lead the URSI Committee of the Federal Republic of Germany, and thereafter became honorary president of this national committee. He served as a Vice-President of URSI from 1963 to 1969 and as President of URSI from 1969 to 1972. In 1978 he was awarded with the title URSI Honorary President.

Dieminger's scientific work comprises about 120 articles on various geophysical and radio wave propagation topics, including landmark papers on ground scatter and the D-region winter anomaly. He also contributed to several books and encyclopaedias, like Brockhaus and Landolt-Börnstein, and he served as an editor of the Zeitschrift für Geophysik from 1961 to 1988.

After his retirement in 1975 he still kept close contacts to the Max-Planck-Institut für Aeronomie and worked on historical and bibliographical publications in his field. In his retirement he now enjoyed his hobbies, amateur radio (already since 1926 !) and model trains.

Dieminger married Dr. rer. techn. Ilse, née Günther in 1935. He is survived by his wife, two sons and a daughter. Walter Dieminger will be remembered as a dedicated scientist, a pleasant colleague, and a responsible Director. He will be missed by all who knew him.

A more detailed version is available in German under: 
Complete list of W. Dieminger's publications.
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