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- Stellar_triangulation abstract "Stellar triangulation is a method of geodesy which uses cosmic instead of terrestrial targets. It was first done by the Finnish geodesist Väisälä in 1959, who made astrometric photographs of the sky at two stations together with a balloon probe between them.Even this first step showed the potential of the method, because Väisälä got the azimuth between Helsinki and Turku (a distance of 150 km) with an accuracy of 1\". Soon the method was successfully tested by ballistic rockets and for some special satellites. Adequate computer programs were written for the astrometric reduction of the photographic plates, the intersection of the \"observation planes\" containing the stations and the targets, and the adjustment of stellar-terrestric networks with redundancy.The advantage of stellar triangulation is the possibility to cross far distances (terrestrial observations are restricted to approx. 30 km, and even in high mountains to 60 km), and the independency of the Earth's gravity field. The results are azimuths between the stations in the stellar-inertial navigation system, despite of no direct line of sight.In 1960 the first appropriate space probe was launched - the 30 m diameter balloon satellite (Project Echo). By then the whole of Western Europe could be linked together geodetically with accuracies 2-10 times better than by classical triangulation.During the late 1960s a global project was begun by H.H. Schmid (Switzerland) to connect 45 stations all over the continents, with distances of 3000 – 5000 km. It was finished in 1974 by precise reduction of some 3000 stellar plates and network adjustment of 46 stations (2 additional ones in Germany and the Pacific, but without the areas of Russia and China). The mean accuracy was between ± 5m (Europe, USA) and 7–10 m (Africa, Antarctica), depending of weather and infrastructure conditions. Combined with Doppler measurements the global accuracy was even 3m. This is more than 20 times better than previously, because the gravity field up to 1974 couldn't be calculated better than 100 meters between distant continents.The use of stars as a reference system wars expanded in the 70s and early 80s for continental networks - but then the laser and electronic measurements became better than 2m and could be carried out automatically. Nowadays some similar techniques are carried out by interferometry with very distant radio quasars instead of optical satellite & star observations. The geodetic connection of radio telescopes is now possible up to mm...cm precision as published periodically by the IVS community. This global project group was founded in 2000 by Harald Schuh (H. Schuh) (Munich/ TU Vienna) and some dozen research projects worldwide, and is now a permanent service of IUGG and IERS. The photographic observations as done 1959 - 1985 are irrelevant now because of their expense, but lead to some renaissance by electro-optical techniques like CCD.".
- Stellar_triangulation wikiPageID "7162656".
- Stellar_triangulation wikiPageLength "4607".
- Stellar_triangulation wikiPageOutDegree "55".
- Stellar_triangulation wikiPageRevisionID "668836464".
- Stellar_triangulation wikiPageWikiLink Azimuth.
- Stellar_triangulation wikiPageWikiLink Balloon.
- Stellar_triangulation wikiPageWikiLink Balloon_satellite.
- Stellar_triangulation wikiPageWikiLink Category:Astrometry.
- Stellar_triangulation wikiPageWikiLink Category:Geodesy.
- Stellar_triangulation wikiPageWikiLink Charge-coupled_device.
- Stellar_triangulation wikiPageWikiLink China.
- Stellar_triangulation wikiPageWikiLink Computer_program.
- Stellar_triangulation wikiPageWikiLink Continent.
- Stellar_triangulation wikiPageWikiLink Data_redundancy.
- Stellar_triangulation wikiPageWikiLink Doppler_effect.
- Stellar_triangulation wikiPageWikiLink ETH_Zurich.
- Stellar_triangulation wikiPageWikiLink Electronics.
- Stellar_triangulation wikiPageWikiLink External_ballistics.
- Stellar_triangulation wikiPageWikiLink Figure_of_the_Earth.
- Stellar_triangulation wikiPageWikiLink Fundamental_station.
- Stellar_triangulation wikiPageWikiLink Geodesy.
- Stellar_triangulation wikiPageWikiLink Germany.
- Stellar_triangulation wikiPageWikiLink Gravitational_field.
- Stellar_triangulation wikiPageWikiLink Handbuch_der_Vermessungskunde.
- Stellar_triangulation wikiPageWikiLink Hellmut_Schmid.
- Stellar_triangulation wikiPageWikiLink Helsinki.
- Stellar_triangulation wikiPageWikiLink Interferometry.
- Stellar_triangulation wikiPageWikiLink International_Earth_Rotation_and_Reference_Systems_Service.
- Stellar_triangulation wikiPageWikiLink International_Union_of_Geodesy_and_Geophysics.
- Stellar_triangulation wikiPageWikiLink International_Valuation_Standards_Council.
- Stellar_triangulation wikiPageWikiLink Intersection_(set_theory).
- Stellar_triangulation wikiPageWikiLink Karl_Ledersteger.
- Stellar_triangulation wikiPageWikiLink Laser.
- Stellar_triangulation wikiPageWikiLink Line-of-sight_propagation.
- Stellar_triangulation wikiPageWikiLink Lockheed_SR-71_Blackbird.
- Stellar_triangulation wikiPageWikiLink Max_Kneissl.
- Stellar_triangulation wikiPageWikiLink Otto_Eggert.
- Stellar_triangulation wikiPageWikiLink PAGEOS.
- Stellar_triangulation wikiPageWikiLink Permanent.
- Stellar_triangulation wikiPageWikiLink Photograph.
- Stellar_triangulation wikiPageWikiLink Project_Echo.
- Stellar_triangulation wikiPageWikiLink Quasar.
- Stellar_triangulation wikiPageWikiLink Radio_telescope.
- Stellar_triangulation wikiPageWikiLink Renaissance.
- Stellar_triangulation wikiPageWikiLink Russia.
- Stellar_triangulation wikiPageWikiLink Satellite_geodesy.
- Stellar_triangulation wikiPageWikiLink Satellite_laser_ranging.
- Stellar_triangulation wikiPageWikiLink Space_probe.
- Stellar_triangulation wikiPageWikiLink Star.
- Stellar_triangulation wikiPageWikiLink Triangulation.
- Stellar_triangulation wikiPageWikiLink Trilateration.
- Stellar_triangulation wikiPageWikiLink Turku.
- Stellar_triangulation wikiPageWikiLink Very-long-baseline_interferometry.
- Stellar_triangulation wikiPageWikiLink Western_Europe.
- Stellar_triangulation wikiPageWikiLink Wilhelm_Jordan_(geodesist).
- Stellar_triangulation wikiPageWikiLink Yrjö_Väisälä.
- Stellar_triangulation wikiPageWikiLinkText "Stellar triangulation".
- Stellar_triangulation wikiPageWikiLinkText "stellar triangulation".
- Stellar_triangulation wikiPageWikiLinkText "triangulation".
- Stellar_triangulation wikiPageUsesTemplate Template:Unreferenced.
- Stellar_triangulation subject Category:Astrometry.
- Stellar_triangulation subject Category:Geodesy.
- Stellar_triangulation hypernym Method.
- Stellar_triangulation type Software.
- Stellar_triangulation type Geophysic.
- Stellar_triangulation type Sub-discipline.
- Stellar_triangulation comment "Stellar triangulation is a method of geodesy which uses cosmic instead of terrestrial targets. It was first done by the Finnish geodesist Väisälä in 1959, who made astrometric photographs of the sky at two stations together with a balloon probe between them.Even this first step showed the potential of the method, because Väisälä got the azimuth between Helsinki and Turku (a distance of 150 km) with an accuracy of 1\".".
- Stellar_triangulation label "Stellar triangulation".
- Stellar_triangulation sameAs Q7607202.
- Stellar_triangulation sameAs m.0h7k91.
- Stellar_triangulation sameAs Q7607202.
- Stellar_triangulation wasDerivedFrom Stellar_triangulation?oldid=668836464.
- Stellar_triangulation isPrimaryTopicOf Stellar_triangulation.