This is an old - not maintained - article of the AEIOU.
In the Austria-Forum you find an updated version of this article in the new AEIOU.
Fourth Cartographical Register, also called "Precision Register", carried out between 1896 and 1914 by the k. u. k. Institute of Military Geography,, between 1915 and 1918 by the k. u. k. War Surveying Office, from 1921 by the Federal Surveying Office, and from 1923 (with interruption in 1938-1945, when the Main Surveying Division XIV of the Reich Office for Surveying was in charge) by the Federal Office for Weights, Measures and Surveying. The survey on a scale of 1 : 25.000 was carried out, until the 1950s, by terrestrial photogrammetry and since then by air survey (aerial photogrammetry). In order to speed up work, from 1959 surveying was carried on a scale of 1 : 50.000 and the old part of the Austrian map on a scale of 1 : 25.000 was abandoned. The Fourth Cartographical Register was completed in 1987. Since that year a complete map of the Austrian territory based on uniform geodetic principles has been available.
Literature: G. Fasching and F. Wawrik, Landesaufnahme und Militärkarten, in: Austria picta, 1989.