World longitude determination
The world longitude determination or international longitude determination was a joint venture in the 1930s to define an intercontinental uniform system for the astronomical longitude . About 50 large, astrometrically well-equipped observatories were involved ; The astronomical meridian plane of Greenwich was agreed as the prime meridian - as has been customary for a long time .
In terms of measurement technology, the project was largely carried out in 1933, the most important method being the local time determination by meridian passages of fundamental stars and the mutual simultaneous time comparison via radio waves. The internal accuracy of the local time determinations was a few milliseconds , the difference in length was 0.01 seconds.
The stations in Europe included a.
- Germany
- Austria
- Switzerland
- France
- Italy
- Spain
- Portugal
- Soviet Union
- Latvia
- University of Latvia Observatory ( Riga )
- also Brussels, Bucharest (2), Charkow, Liège, Posen, Riga, Sofia and Warsaw (2).
See also
source
- Heidelberg Yearbook 1956