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geodesy
geodesy or geodetic surveying, theory and practice of determining the position of points on the earth's surface and the dimensions of areas so large that the curvature of the earth must be taken into account. It is distinguished from plane surveying , the operations of which are executed without regard to the earth's curvature. In geodetic surveying, two points, called stations, many miles apart are selected, and the latitude and longitude of each is determined by astronomical means. The line between these two points, the base line, is measured with a high degree of accuracy. The position of a third station is determined by the angle it makes with each end of the base line. This process, called triangulation, is continued until the whole area to be surveyed is mapped. For indicating a triangulation station the U.S. Coast and Geodetic Survey uses a bronze disk suitably marked and having a projection on the bottom for anchoring it in concrete. Where the curvature of the earth is great or where there are hills or high trees between stations, towers are built so that one station may be seen from another. In recent years, artificial earth satellites have come into wide use as geodetic instruments. Shifts in the orbits of the satellites Explorer I and Vanguard I provided data by which geodesists corrected the value for the oblateness of the earth. This led to a program of geodetic satellites specifically designed to measure variations in the earth's gravitational field, and to determine the exact geographic position of points on the earth's surface. A triangulation station in space, the geodetic satellite, is photographed against the background of stars in order to compare accurately the relative positions of points on the earth. |
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"geodesy." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "geodesy." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1E1-geodesy.html "geodesy." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-geodesy.html |
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geodesy
ge·od·e·sy / jēˈädəsē/ • n. the branch of mathematics dealing with the shape and area of the earth or large portions of it. DERIVATIVES: ge·od·e·sist / -sist/ n. |
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"geodesy." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "geodesy." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O999-geodesy.html "geodesy." The Oxford Pocket Dictionary of Current English. 2009. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-geodesy.html |
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geodesy
geodesy †land-surveying XVI; (math.) study which determines areas of the earth's surface XIX. — F. géodésie or modL. geōdæsia — Gr. geōdaisíā (daiein divide).
Hence geodetic XVII. |
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T. F. HOAD. "geodesy." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. T. F. HOAD. "geodesy." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O27-geodesy.html T. F. HOAD. "geodesy." The Concise Oxford Dictionary of English Etymology. 1996. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O27-geodesy.html |
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geodesy
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AILSA ALLABY and MICHAEL ALLABY. "geodesy." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "geodesy." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O13-geodesy.html AILSA ALLABY and MICHAEL ALLABY. "geodesy." A Dictionary of Earth Sciences. 1999. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-geodesy.html |
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geodesy
geodesy The study of the shape and dimensions of the Earth, or any other solid planetary body.
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"geodesy." A Dictionary of Astronomy. 1997. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "geodesy." A Dictionary of Astronomy. 1997. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O80-geodesy.html "geodesy." A Dictionary of Astronomy. 1997. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-geodesy.html |
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