ED50
geodetic datum
ED50 ("European Datum 1950", EPSG:4230) is a geodetic datum which was defined after World War II for the international connection of geodetic networks.
Background
Some of the important battles of World War II were fought on the borders of Germany, the Netherlands, Belgium and France, and the mapping of these countries had incompatible latitude and longitude positioning. During the war the German Military Survey (Reichsamt Kriegskarten und Vermessungswesen), under the command of Lieutenant General Gerlach Hemmerich, began systematically mapping the portion of Europe under German military control. The Allies were also concerned about the state of mapping in Europe, and in 1944 the US Army Map Service set up an intelligence team to collect mapping and surveying information from the Germans as the allied armies moved through Europe after the Normandy landings. The group, known as Houghteam after Major Floyd W. Hough, collected much material. Their greatest success was in April 1945, when they found the entire geodetic archives of the German Army cached in Saalfeld, Thuringia. The shipment, 75 truckloads in all, was transferred to Bamberg, and then to Washington for evaluation.
Shortly afterward, the team captured the personnel of the Reichsamt für Landesaufnahme, the State Surveying Service, in Friedrichroda, Thuringia. This group had been working under renowned geodesist Professor Erwin Gigas to integrate the mapping of the occupied territories with that of Germany. They were directed to continue this work in US-occupied Bamberg, as part of the US-led effort to develop a single adjusted triangulation for Central Europe.
Begin with the source’s own compact description: “ED50” is geodetic datum. The dossier treats that line as a proposition to test through ED50, geodetic and datum, not as a finished interpretation.
Why this record matters
The phrase “geodetic datum” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated May 1, 2026. The linked authority identifier is Q1378064. Authority coordinates are 52.381, 13.066. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1950, 1944 and 1945.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “ED50”, its source revision and the description used here.
- Expand the search: follow ED50 primary sources, ED50 archive and ED50 research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “ED50”?
- Which cited source is closest to the event, object or claim?
- What terminology or title could unlock a more precise catalogue search?
Search terms from this dossier
This entry incorporates text from “ED50” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.