ED 50 (European Datum 1950) is a geodetic datum which was defined after World War II for the international connection of geodetic networks. A Geodetic Datum is an adjustment to position of origin and shape of the planet, used by cartographers and satellite navigation systems to translate positions indicated on their products to their real position on earth. ... World War II was a truly global conflict with many facets: immense human suffering, fierce indoctrinations, and the use of new, extremely devastating weapons like the atom bomb. ... A geodetic network is a network of triangles which are measured exactly by techniques of terrestrial surveying or by satellite geodesy. ...

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. This led to the setting up of ED50 as a consistent mapping datum for much of Western Europe. It was, and still is, used in much of Western Europe apart from Great Britain, Ireland, Sweden and Switzerland, which have their own datums.

It was based on the international Ellipsoid of 1909 resp. 1924 ("Hayford"-Ellipsoid) ( radius of the Earth's equator 6378,388 km, flattening 1:297) and widely used all over the world up to the 1980s, when GRS80 and WGS84 were established. 1924 was a leap year starting on Tuesday (link will take you to calendar). ... John Fillmore Hayford (1868-1925), eminent United States geodesist. ... The radius of the Earth is the distance from the Earths centre to its surface at mean sea level. ... The equator is an imaginary line drawn around a planet, halfway between the poles. ... The flattening of an ellipsoid is the relative difference between its equatorial radius a and its polar radius b: f = (a - b) / a The flattening of the Earth is 1:298,25 (which corresponds to a radius difference of 21 km of the Earth radius 6357 - 6378 km) and would... // Events and trends The 1980s marked an abrupt shift towards more conservative lifestyles after the momentous cultural revolutions which took place in the 60s and 70s and the definition of the AIDS virus in 1981. ... Definition GRS 80, or Geodetic Reference System 1980, is a geodetic reference system consisting of a global reference ellipsoid and a gravity field model. ... WGS 84 is the 1984 revision of the World Geodetic System. ...

Many national coordinate systems of Gauss-Krüger are defined by ED50 and oriented by means of Geodetic Astronomy. Up to now it has been used in data bases of gravity field, cadastre, small surveying networks in Europe and America, and by some developing countries with no modern baselines. A database is an information set with a regular structure. ... Cadastre (a French word from the Late Latin capitastrum, a register of the poll-tax) is a register of the real property of a country, with details of the area, the owners and the value. ... Surveyor at work Surveying is the art and science of accurately determining the position of points and the distances between them. ...

The geodetic datum of ED50 is centred at the Frauenkirche of Munich in Southern Germany, where the approximate centre of the Western Europe national networks was situated in the years of the cold war. ED50 was also part of the fundamentals of the NATO coordinates (Gauss Krüger and UTM) up to the 1980s. Frauenkirche is from the German language meaning Church of Our Lady, in reference to the Blessed Virgin Mary. ... Munich: Frauenkirche and Town Hall steeple Munich (German: München (pronounced listen) is the state capital of the German state of Bavaria. ... For the generic term for a high-tension rivalry between countries, see cold war (war). ... The flag of NATO NATO 2002 Summit in Prague The North Atlantic Treaty Organisation (NATO), sometimes called North Atlantic Alliance, Atlantic Alliance or the Western Alliance, is an international organisation for defence collaboration established in 1949, in support of the North Atlantic Treaty signed in Washington, D.C., on April... Universal Transverse Mercator, a map projection Universal Turing Machine University of Tennessee at Martin University of Toronto at Mississauga This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... // Events and trends The 1980s marked an abrupt shift towards more conservative lifestyles after the momentous cultural revolutions which took place in the 60s and 70s and the definition of the AIDS virus in 1981. ...

Datum shift between ED50 and WGS84

The longitude and latitude lines on the two datums are the same in the Archangel region of north-west Russia. As one moves westwards across Europe, the longitude lines on ED50 gradually become further west than their WGS84 equivalents, and are around 100 metres west in Spain and Portugal. Moving southwards, the latitude lines on ED50 gradually become further south than the WGS84 lines, and are around 100 m south in the Mediterranean Sea. (NB. If the lines are further west, the longitude value of any given point becomes more easterly. Similarly, if the lines are south, the values become northerly.) Satellite image The Mediterranean Sea is a part of the Atlantic Ocean almost completely enclosed by land, on the north by Europe, on the south by Africa, and on the east by Asia. ...

The datum shift for the Universal Transverse Mercator grid is different. The eastings vary between 0 m in Eastern Europe and 100 m in the far west of the continent, roughly similar to the longitude shift, but the northings are about 200 m different across Europe, with the ED50 UTM northing lines south of the WGS84 UTM northing lines, as UTM northings are measured from the Equator, and the theoretical ED50 Equator is about 200 m south of the WGS84 one. A transverse Mercator projection is a map projection similar to the Mercator projection in that it is a projection of Earth on a tangent cylinder by rays radial with respect to the cylinder. ...

See also

• The Great Britain datum OSGB36.