Geodesy (pronounced /dʒiːˈɒdɪsi/^{[1]}), also called geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravity field, in a threedimensional time varying space.^{[2]} Besides the Earth's gravity field, geodesists study also geodynamical phenomena such as crustal motion, tides, and polar motion. For this they design global and national Control networks, using Space and terrestrial techniques while relying on datums and coordinate systems. Image File history File links Download high resolution version (960x1280, 533 KB) Geodetic point (1855); Stene, Ostend, Belgium File links The following pages link to this file: Geodesy ...
Image File history File links Download high resolution version (960x1280, 533 KB) Geodetic point (1855); Stene, Ostend, Belgium File links The following pages link to this file: Geodesy ...
The esplanade with the Thermae Palace, the former Royal Residence and the casino For other uses, see Ostend (disambiguation). ...
Image File history File links Download high resolution version (1600x1200, 518 KB) Archive of the Landesamt fÃ¼r Vermessung und Geoinformation, containing a couple of hindred tons of stone litography plates with maps of Bavaria Picture taken as part of the Lange Nacht der Museen in Munich See also Image...
Image File history File links Download high resolution version (1600x1200, 518 KB) Archive of the Landesamt fÃ¼r Vermessung und Geoinformation, containing a couple of hindred tons of stone litography plates with maps of Bavaria Picture taken as part of the Lange Nacht der Museen in Munich See also Image...
For other uses, see Munich (disambiguation). ...
Lithography is a method for printing on a smooth surface. ...
For other uses, see Bavaria (disambiguation). ...
Earth science (also known as geoscience or the geosciences), is an allembracing term for the sciences related to the planet Earth. ...
This article is about Earth as a planet. ...
Gravity is a force of attraction that acts between bodies that have mass. ...
An Australian based componey that produces Geothermal Power uning Hot Dry Rocks (HDR) It is supported by the Australian goverment Geodynamics Category: ...
Earth cutaway from core to exosphere. ...
This article is about tides in the Earths oceans. ...
This article needs to be wikified. ...
A Control network or simply Control, is a set of referencepoints of known geospatial coordinates. ...
In Geodesy, the term Space techniques includes modern measuring methods which make use of artificial satellites, interplanetary space probes and of quasars. ...
It has been suggested that this article or section be merged with Geodetic system. ...
In mathematics as applied to geometry, physics or engineering, a coordinate system is a system for assigning a tuple of numbers to each point in an ndimensional space. ...
Definition
Geodesy (from Greek Γεωδαισία lit. division of the Earth) is primarily concerned with positioning within the temporally varying gravity field. Somewhat obsolete nowadays, geodesy in the German speaking world is divided into "Higher Geodesy" ("Erdmessung" or "höhere Geodäsie"), which is concerned with measuring the Earth on the global scale, and "Practical Geodesy" or "Engineering Geodesy" ("Ingenieurgeodäsie"), which is concerned with measuring specific parts or regions of the Earth, and which includes surveying. Look up time in Wiktionary, the free dictionary. ...
Surveyor at work with a leveling instrument. ...
The shape of the Earth is to a large extent the result of its rotation, which causes its equatorial bulge, and the competition of geological processes such as the collision of plates and of vulcanism, resisted by the Earth's gravity field. This applies to the solid surface, the liquid surface (dynamic sea surface topography) and the Earth's atmosphere. For this reason, the study of the Earth's gravity field is called physical geodesy by some. Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station For other uses, see Volcano (disambiguation). ...
Gravity is a force of attraction that acts between bodies that have mass. ...
Dynamic sea surface topography is the average difference between the actual surface of the Earth and a geoid. ...
Air redirects here. ...
The gravity field is the field of force, caused by the gravitation of the Earth, and influenced by the Earth rotation, the atmosphere and by geological bodies. ...
Definition Physical geodesy is the study of the physical properties of the gravity field of the Earth, the geopotential, with a view to their application in geodesy. ...
History 
Main article: History of geodesy Man has always been interested in the Earth on which he lives. ...
Geoid and reference ellipsoid The geoid is essentially the figure of the Earth abstracted from its topographical features. It is an idealized equilibrium surface of sea water, the mean sea level surface in the absence of currents, air pressure variations etc. and continued under the continental masses. The geoid, unlike ellipsoid, is irregular and too complicated to serve as the computational surface on which to solve geometrical problems like point positioning. The geometrical separation between it and the reference ellipsoid is called the geoidal undulation. It varies globally between ±110 m. The GOCE project will measure highaccuracy gravity gradients and provide an accurate geoid model based on the Earths gravity field. ...
For considerations of sea level change, in particular rise associated with possible global warming, see sea level rise. ...
3D rendering of an ellipsoid In mathematics, an ellipsoid is a type of quadric that is a higher dimensional analogue of an ellipse. ...
A reference ellipsoid, customarily chosen to be the same size (volume) as the geoid, is described by its semimajor axis (equatorial radius) a and flattening f. The quantity f = (a−b)/a, where b is the semiminor axis (polar radius), is a purely geometrical one. The mechanical ellipticity of the Earth (dynamical flattening, symbol J_{2}) can be determined to high precision by observation of satellite orbit perturbations. Its relationship with the geometrical flattening is indirect. The relationship depends on the internal density distribution, or, in simplest terms, the degree of central concentration of mass. In geodesy, a reference ellipsoid is a mathematicallydefined surface that approximates the geoid, the truer figure of the Earth, or other planetary body. ...
The 1980 Geodetic Reference System (GRS80) posited a 6,378,137 m semimajor axis and a 1:298.257 flattening. This system was adopted at the XVII General Assembly of the International Union of Geodesy and Geophysics (IUGG). It is essentially the basis for geodetic positioning by the Global Positioning System and is thus also in extremely widespread use outside the geodetic community. Definition GRS 80, or Geodetic Reference System 1980, is a geodetic reference system consisting of a global reference ellipsoid and a gravity field model. ...
The International Union of Geodesy and Geophysics, or IUGG, is a nongovernmental organisation dedicated to the scientific study of the Earth and to the application of the knowledge gained to the needs of society that was established in 1919. ...
The numerous other systems which have been used by diverse countries for their maps and charts are gradually dropping out of use as more and more countries move to global, geocentric reference systems using the GRS80 reference ellipsoid.
Coordinate systems in space The locations of points in threedimensional space are most conveniently described by three cartesian or rectangular coordinates, X,Y and Z. Since the advent of satellite positioning, such coordinate systems are typically geocentric: the Z axis is aligned with the Earth's (conventional or instantaneous) rotation axis. Fig. ...
Prior to satellite geodesy era, the coordinate systems associated with a geodetic datum attempted to be geocentric, but their origins differed from the geocentre by hundreds of metres, due to regional deviations in the direction of the plumbline (vertical). These regional geodetic datums, such as ED50 (European Datum 1950) or NAD83 (North American Datum 1983) have ellipsoids associated with them that are regional 'best fits' to the geoids within their areas of validity, minimising the deflections of the vertical over these areas. Satellite geodesy is the measurement of the form and dimensions of the Earth, the location of objects on its surface and the figure of the Earths gravity field by means of satellite techniques. ...
It has been suggested that this article or section be merged with Geodetic system. ...
The geocentric model (in Greek: geo = earth and centron = centre) of the universe is a paradigm which places the Earth at its center. ...
Vertical of an alpine point: note its curvature. ...
ED 50 (European Datum 1950) is a geodetic datum which was defined after World War II for the international connection of geodetic networks. ...
The North American Datum is the official reference ellipsoid used for the primary geodetic network in North America. ...
The GOCE project will measure highaccuracy gravity gradients and provide an accurate geoid model based on the Earths gravity field. ...
It is only because GPS satellites orbit about the geocentre, that this point becomes naturally the origin of a coordinate system defined by satellite geodetic means, as the satellite positions in space are themselves computed in such a system. GPS redirects here. ...
Geocentric coordinate systems used in geodesy can be divided naturally into two classes:  Inertial reference systems, where the coordinate axes retain their orientation relative to the fixed stars, or equivalently, to the rotation axes of ideal gyroscopes; the X axis points to the vernal equinox
 Corotating, also ECEF ("Earth Centred, Earth Fixed"), where the axes are attached to the solid body of the Earth. The X axis lies within the Greenwich observatory's meridian plane.
The coordinate transformation between these two systems is described to good approximation by (apparent) sidereal time, which takes into account variations in the Earth's axial rotation (lengthofday variations). A more accurate description also takes polar motion into account, a phenomenon closely monitored by geodesists. In physics, an inertial frame of reference, or inertial frame for short (also descibed as absolute frame of reference), is a frame of reference in which the observers move without the influence of any accelerating or decelerating force. ...
A fixed star is a celestial object that does not seem to move (in comparison to the other stars of the night sky). ...
A gyroscope is a device which demonstrates the principle of conservation of angular momentum, in physics. ...
Illumination of Earth by Sun on the day of equinox The vernal equinox (or spring equinox) marks the beginning of astronomical spring. ...
The Prime Meridian, Greenwich The Prime Meridian is the meridian (line of longitude) passing through the Royal Greenwich Observatory, Greenwich, England; it is the meridian at which longitude is 0 degrees. ...
On the earth, a meridian is a northsouth line between the North Pole and the South Pole. ...
Sidereal time is time measured by the apparent diurnal motion of the vernal equinox, which is very close to, but not identical with, the motion of stars. ...
Look up day in Wiktionary, the free dictionary. ...
This article needs to be wikified. ...
Coordinate systems in the plane In surveying and mapping, important fields of application of geodesy, two general types of coordinate systems are used in the plane: Surveyor at work with a leveling instrument. ...
The word mapping has several senses: In mathematics and related technical fields, it is some kind of function: see map (mathematics). ...
 Planopolar, in which points in a plane are defined by a distance s from a specified point along a ray having a specified direction α with respect to a base line or axis;
 Rectangular, points are defined by distances from two perpendicular axes called x and y. It is geodetic practice — contrary to the mathematical convention — to let the x axis point to the North and the y axis to the East.
Rectangular coordinates in the plane can be used intuitively with respect to one's current location, in which case the x axis will point to the local North. More formally, such coordinates can be obtained from threedimensional coordinates using the artifice of a map projection. It is not possible to map the curved surface of the Earth onto a flat map surface without deformation. The compromise most often chosen — called a conformal projection — preserves angles and length ratios, so that small circles are mapped as small circles and small squares as squares. The Mercator projection shows courses of constant bearing as straight lines. ...
In mathematics, a conformal map is a function which preserves angles. ...
An example of such a projection is UTM (Universal Transverse Mercator). Within the map plane, we have rectangular coordinates x and y. In this case the North direction used for reference is the map North, not the local North. The difference between the two is called meridian convergence. 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. ...
It is easy enough to "translate" between polar and rectangular coordinates in the plane: let, as above, direction and distance be α and s respectively, then we have The reverse translation is slightly more tricky.
Heights In geodesy, point or terrain heights are "above sea level", an irregular, physically defined surface. Therefore a height should ideally not be referred to as a coordinate. It is more like a physical quantity, and though it can be tempting to treat height as the vertical coordinate z, in addition to the horizontal coordinates x and y, and though this actually is a good approximation of physical reality in small areas, it quickly becomes invalid for regional considerations.^{[specify]} Height is the measurement of distance between a specified point and a corresponding plane of reference. ...
For considerations of sea level change, in particular rise associated with possible global warming, see sea level rise. ...
Heights come in the following variants:  Orthometric heights
 Normal heights
 Geopotential heights
Each has its advantages and disadvantages. Both orthometric and normal heights are heights in metres above sea level, whereas geopotential numbers are measures of potential energy (unit: m² s^{−2}) and not metric. Orthometric and normal heights differ in the precise way in which mean sea level is conceptually continued under the continental masses. The reference surface for orthometric heights is the geoid, an equipotential surface approximating mean sea level. The orthometric height is the distance H along a line of force from a given point P at the physical surface of an object to the geoid. ...
The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...
Geopotential height is a vertical coordinate referenced to Earths mean sea level â€” an adjustment to geometric height (elevation above mean sea level) using the variation of gravity with latitude and elevation. ...
The GOCE project will measure highaccuracy gravity gradients and provide an accurate geoid model based on the Earths gravity field. ...
None of these heights is in any way related to geodetic or ellipsoidial heights, which express the height of a point above the reference ellipsoid. Satellite positioning receivers typically provide ellipsoidal heights, unless they are fitted with special conversion software based on a model of the geoid. In geodesy, a reference ellipsoid is a mathematicallydefined surface that approximates the geoid, the truer figure of the Earth, or other planetary body. ...
The GOCE project will measure highaccuracy gravity gradients and provide an accurate geoid model based on the Earths gravity field. ...
Geodetic data Because geodetic point coordinates (and heights) are always obtained in a system that has been constructed itself using real observations, geodesists introduce the concept of a geodetic datum: a physical realization of a coordinate system used for describing point locations. The realization is the result of choosing conventional coordinate values for one or more datum points. In the case of height datums, it suffices to choose one datum point: the reference bench mark, typically a tide gauge at the shore. Thus we have vertical datums like the NAP (Normaal Amsterdams Peil), the North American Vertical Datum 1988 (NAVD88), the Kronstadt datum, the Trieste datum, and so on. Normaal Amsterdams Peil (NAP) or Amsterdam Ordnance Datum is a vertical datum in use in large parts of Western Europe. ...
In case of plane or spatial coordinates, we typically need several datum points. A regional, ellipsoidal datum like ED50 can be fixed by prescribing the undulation of the geoid and the deflection of the vertical in one datum point, in this case the Helmert Tower in Potsdam. However, an overdetermined ensemble of datum points can also be used. ED 50 (European Datum 1950) is a geodetic datum which was defined after World War II for the international connection of geodetic networks. ...
The GOCE project will measure highaccuracy gravity gradients and provide an accurate geoid model based on the Earths gravity field. ...
Potsdam is the capital city of the federal state of Brandenburg in Germany. ...
Changing the coordinates of a point set referring to one datum, so to make them refer to another datum, is called a datum transformation. In the case of vertical datums, this consists of simply adding a constant shift to all height values. In the case of plane or spatial coordinates, datum transformation takes the form of a similarity or Helmert transformation, consisting of a rotation and scaling operation in addition to a simple translation. In the plane, a Helmert transformation has four parameters, in space, seven.
A note on terminology In the abstract, a coordinate system as used in mathematics and geodesy is, e.g., in ISO terminology, referred to as a coordinate system. International geodetic organizations like the IERS (International Earth Rotation and Reference Systems Service) speak of a reference system. â€œISOâ€ redirects here. ...
The International Earth Rotation Service (IERS) is the body responsible for maintaining global time and reference frame standards, notably through its Earth Orientation Paramater (EOP) and International Celestial Reference System (ICRS) groups. ...
When these coordinates are realized by choosing datum points and fixing a geodetic datum, ISO uses the terminology coordinate reference system, while IERS speaks of a reference frame. A datum transformation again is referred to by ISO as a coordinate transformation. (ISO 19111: Spatial referencing by coordinates).
Point positioning Point positioning is the determination of the coordinates of a point on land, at sea, or in space with respect to a coordinate system. Point position is solved by computation from measurements linking the known positions of terrestrial or extraterrestrial points with the unknown terrestrial position. This may involve transformations between or among astronomical and terrestrial coordinate systems. The known points used for point positioning can be triangulation points of a higher order network, or GPS satellites. Triangulation can be used to find the distance from the shore to the ship. ...
GPS redirects here. ...
Traditionally, a hierarchy of networks has been built to allow point positioning within a country. Highest in the hierarchy were triangulation networks. These were densified into networks of traverses (polygons), into which local mapping surveying measurements, usually with measuring tape, corner prism and the familiar red and white poles, are tied. In fortification, a traverse is a mass of earth or other material employed to protect troops against enfilade. ...
A polygon (from the Greek poly, for many, and gonos, for angle) is a closed planar path composed of a finite number of sequential straight line segments. ...
Nowadays all but special measurements (e.g., underground or high precision engineering measurements) are performed with GPS. The higher order networks are measured with static GPS, using differential measurement to determine vectors between terrestrial points. These vectors are then adjusted in traditional network fashion. A global polyhedron of permanently operating GPS stations under the auspices of the IERS is used to define a single global, geocentric reference frame which serves as the "zero order" global reference to which national measurements are attached. GPS redirects here. ...
The International Earth Rotation Service (IERS) is the body responsible for maintaining global time and reference frame standards, notably through its Earth Orientation Paramater (EOP) and International Celestial Reference System (ICRS) groups. ...
For surveying mappings, frequently Real Time Kinematic GPS is employed, tying in the unknown points with known terrestrial points close by in real time. Surveyor at work with a leveling instrument. ...
Real Time Kinematic (RTK) land survey is based on a differential use of carrier phase measurements of the GPS, Glonass and/or Galileo signals where a single reference station provides the realtime corrections of even to a centimetre level of accuracy. ...
One purpose of point positioning is the provision of known points for mapping measurements, also known as (horizontal and vertical) control. In every country, thousands of such known points exist and are normally documented by the national mapping agencies. Surveyors involved in real estate and insurance will use these to tie their local measurements to.
Geodetic problems In geometric geodesy, two standard problems exist:
First geodetic problem  Given a point (in terms of its coordinates) and the direction (azimuth) and distance from that point to a second point, determine (the coordinates of) that second point.
Azimuth is the horizontal component of a direction (compass direction), measured around the horizon, from the north toward the east (i. ...
Second (inverse) geodetic problem  Given two points, determine the azimuth and length of the line (straight line, arc or geodesic) that connects them.
In the case of plane geometry (valid for small areas on the Earth's surface) the solutions to both problems reduce to simple trigonometry. On the sphere, the solution is significantly more complex, e.g., in the inverse problem the azimuths will differ between the two end points of the connecting great circle, arc, i.e. the geodesic. Wikibooks has a book on the topic of Trigonometry All of the trigonometric functions of an angle Î¸ can be constructed geometrically in terms of a unit circle centered at O. Trigonometry (from Greek trigÅnon triangle + metron measure[1]), informally called trig, is a branch of mathematics that deals with...
For the Brisbane bus routes known collectively as the Great Circle Line (598 & 599), see the following list of Brisbane Transport routes A great circle on a sphere A great circle is a circle on the surface of a sphere that has the same diameter as the sphere, dividing the...
On the ellipsoid of revolution, solutions in closed form do not exist, so rapidly converging series expansions have traditionally been used, such as Vincenty's formulae. In the general case, the solution is called the geodesic for the surface considered. It may be nonexistent or nonunique. The differential equations for the geodesic can be solved numerically, e.g., in MATLAB. In mathematics, a geodesic is a generalization of the notion of a straight line to curved spaces. In presence of a metric, geodesics are defined to be (locally) the shortest path between points on the space. ...
Visualization of airflow into a duct modelled using the NavierStokes equations, a set of partial differential equations. ...
In mathematics, a geodesic is a generalization of the notion of a straight line to curved spaces. In presence of a metric, geodesics are defined to be (locally) the shortest path between points on the space. ...
Not to be confused with Matlab Upazila in Chandpur District, Bangladesh. ...
Geodetic observational concepts Here we define some basic observational concepts, like angles and coordinates, defined in geodesy (and astronomy as well), mostly from the viewpoint of the local observer.  The plumbline or vertical is the direction of local gravity, or the line that results by following it. It is slightly curved.
 The zenith is the point on the celestial sphere where the direction of the gravity vector in a point, extended upwards, intersects it. More correct is to call it a <direction> rather than a point.
 The nadir is the opposite point (or rather, direction), where the direction of gravity extended downward intersects the (invisible) celestial sphere.
 The celestial horizon is a plane perpendicular to a point's gravity vector.
 Azimuth is the direction angle within the plane of the horizon, typically counted clockwise from the North (in geodesy and astronomy) or South (in France).
 Elevation is the angular height of an object above the horizon, Alternatively zenith distance, being equal to 90 degrees minus elevation.
 Local topocentric coordinates are azimuth (direction angle within the plane of the horizon) and elevation angle (or zenith angle) and distance.
 The North celestial pole is the extension of the Earth's (precessing and nutating) instantaneous spin axis extended Northward to intersect the celestial sphere. (Similarly for the South celestial pole.)
 The celestial equator is the intersection of the (instantaneous) Earth equatorial plane with the celestial sphere.
 A meridian plane is any plane perpendicular to the celestial equator and containing the celestial poles.
 The local meridian is the plane containing the direction to the zenith and the direction to the celestial pole.
Vertical of an alpine point: note its curvature. ...
In broad terms, the zenith is the direction pointing directly above a particular location (perpendicular, orthogonal). ...
The celestial sphere is divided by the celestial equator. ...
For other uses, see Nadir (disambiguation). ...
Azimuth is the horizontal component of a direction (compass direction), measured around the horizon, from the north toward the east (i. ...
Elevation histogram of the surface of the Earth â€“ approximately 71% of the Earths surface is covered with water. ...
The two celestial poles are the imaginary points where the Earths spin axis intersects the imaginary rotating sphere of gigantic radius, called the celestial sphere. ...
Precession redirects here. ...
Rotation (green), Precession (blue) and Nutation (red) of the Earth Nutation is a slight irregular motion (etymologically a nodding) in the axis of rotation of a largely axially symmetric object, such as a gyroscope or a planet. ...
On the earth, a meridian is a northsouth line between the North Pole and the South Pole. ...
Geodetic measurements The level is used for determining height differences and height reference systems, commonly referred to mean sea level. The traditional spirit level produces these practically most useful heights above sea level directly; the more economical use of GPS instruments for height determination requires precise knowledge of the figure of the geoid, as GPS only gives heights above the GRS80 reference ellipsoid. As geoid knowledge accumulates, one may expect use of GPS heighting to spread. Look up level in Wiktionary, the free dictionary. ...
For considerations of sea level change, in particular rise associated with possible global warming, see sea level rise. ...
A spirit level A spirit level or bubble level is an instrument designed to indicate whether a surface is level or plumb. ...
The GOCE project will measure highaccuracy gravity gradients and provide an accurate geoid model based on the Earths gravity field. ...
Definition GRS 80, or Geodetic Reference System 1980, is a geodetic reference system consisting of a global reference ellipsoid and a gravity field model. ...
The theodolite is used to measure horizontal and vertical angles to target points. These angles are referred to the local vertical. The tacheometer additionally determines, electronically or electrooptically, the distance to target, and is highly automated to even robotic in its operations. The method of free station position is widely used. An optical theodolite, manufactured in the Soviet Union in 1958 and used for topographic surveying. ...
The tacheometer or tachymeter is a kind of theodolite used for rapid measurments and determines, electronically or electrooptically, the distance to target, and is highly automated in its operations. ...
For local detail surveys, tacheometers are commonly employed although the oldfashioned rectangular technique using angle prism and steel tape is still an inexpensive alternative. Realtime kinematic (RTK) GPS techniques are used as well. Data collected are tagged and recorded digitally for entry into a Geographic Information System (GIS) database. GIS redirects here. ...
This article is about computing. ...
Geodetic GPS receivers produce directly threedimensional coordinates in a geocentric coordinate frame. Such a frame is, e.g., WGS84, or the frames that are regularly produced and published by the International Earth Rotation and Reference Systems Service (IERS). GPS redirects here. ...
The geocentric model (in Greek: geo = earth and centron = centre) of the universe is a paradigm which places the Earth at its center. ...
WGS 84 is the 1984 revision of the World Geodetic System. ...
The International Earth Rotation Service (IERS) is the body responsible for maintaining global time and reference frame standards, notably through its Earth Orientation Paramater (EOP) and International Celestial Reference System (ICRS) groups. ...
GPS receivers have almost completely replaced terrestrial instruments for largescale base network surveys. For Planetwide geodetic surveys, previously impossible, we can still mention Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR) and Very Long Baseline Interferometry (VLBI) techniques. All these techniques also serve to monitor Earth rotation irregularities as well as plate tectonic motions. In satellite laser ranging (SLR) a global network of observation stations measure the round trip time of flight of ultrashort pulses of light to satellites equipped with retroreflectors. ...
The Lunar Laser Ranging Experiment from the Apollo 11 mission The ongoing Lunar Laser Ranging Experiment was first made possible by a lunar laser ranging retroreflector array planted on the Moon on July 21, 1969, by the crew of the Apollo 11. ...
Very Long Baseline Interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy, in which the data received at each antenna in the array is paired with timing information, usually from a local atomic clock, and then stored for later analysis on magnetic tape or hard disk. ...
Gravity is measured using gravimeters. Basically, there are two kinds of gravimeters. Absolute gravimeters, which nowadays can also be used in the field, are based directly on measuring the acceleration of free fall (for example, of a reflecting prism in a vacuum tube). They are used for establishing the vertical geospatial control. Most common relative gravimeters are spring based. They are used in gravity surveys over large areas for establishing the figure of the geoid over these areas. Most accurate relative gravimeters are superconducting gravimeters, and these are sensitive to one thousandth of one billionth of the Earth surface gravity. Twentysome superconducting gravimeters are used worldwide for studying Earth tides, rotation, interior, and ocean and atmospheric loading, as well as for verifying the Newtonian constant of gravitation. Gravity is a force of attraction that acts between bodies that have mass. ...
A gravimeter is a device designed to measure the local gravitational field. ...
This article is about tides in the Earths oceans. ...
This article is about rotation as a movement of a physical body. ...
Animated map exhibiting the worlds oceanic waters. ...
Gravity redirects here. ...
Units and measures on the ellipsoid Geographical latitude and longitude are stated in the units degree, minute of arc, and second of arc. They are angles, not metric measures, and describe the direction of the local normal to the reference ellipsoid of revolution. This is approximately the same as the direction of the plumbline, i.e., local gravity, which is also the normal to the geoid surface. For this reason, astronomical position determination  measuring the direction of the plumbline by astronomical means  works fairly well provided an ellipsoidal model of the figure of the Earth is used. This article is about the geographical term. ...
Longitude is the eastwest geographic coordinate measurement most commonly utilized in cartography and global navigation. ...
In geodesy, a reference ellipsoid is a mathematicallydefined surface that approximates the geoid, the truer figure of the Earth, or other planetary body. ...
One geographical mile, defined as one minute of arc on the equator, equals 1,855.32571922 m. One nautical mile is one minute of astronomical latitude. The radius of curvature of the ellipsoid varies with latitude, being the longest at the pole and the shortest at the equator as is the nautical mile. A metre was originally defined as the 40millionth part of the length of a meridian (the target wasn't quite reached in actual implementation, so that is off by 0.02% in the current definitions). This means that one kilometre is roughly equal to (1/40,000) * 360 * 60 meridional minutes of arc, which equals 0.54 nautical mile, though this is not exact because the two units are defined on different bases (the international nautical mile is defined as exactly 1,852 m, corresponding to a rounding of 1000/0.54 m to four digits).
Temporal change In geodesy, temporal change can be studied by a variety of techniques. Points on the Earth's surface change their location due to a variety of mechanisms:  Continental plate motion, plate tectonics
 Episodic motion of tectonic origin, esp. close to fault lines
 Periodic effects due to Earth tides
 Postglacial land uplift due to isostatic adjustment
 Various anthropogenic movements due to, for instance, petroleum or water extraction or reservoir construction.
The science of studying deformations and motions of the Earth's crust and the solid Earth as a whole is called geodynamics. Often, study of the Earth's irregular rotation is also included in its definition. The tectonic plates of the world were mapped in the second half of the 20th century. ...
A glaciation (a created composite term meaning Glacial Period, referring to the Period or Era of, as well as the process of High Glacial Activity), often called an ice age, is a geological phenomenon in which massive ice sheets form in the Arctic and Antarctic and advance toward the equator. ...
Petro redirects here. ...
An Australian based componey that produces Geothermal Power uning Hot Dry Rocks (HDR) It is supported by the Australian goverment Geodynamics Category: ...
Techniques for studying geodynamic phenomena on the global scale include: GPS redirects here. ...
Very Long Baseline Interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy, in which the data received at each antenna in the array is paired with timing information, usually from a local atomic clock, and then stored for later analysis on magnetic tape or hard disk. ...
Lidar (light detection and ranging) is a technology that determines distance to an object or surface using laser pulses. ...
For the town in Russia, see Insar. ...
Famous geodesists Math./ Geodesists before ~1900  Abu Rayhan Biruni 9731048, Khwarezm (Iran/Persia)^{[3]}^{[4]}
 Sir George Biddell Airy 18011892, Cambridge & London
 Muhammad alIdrisi 11001166, (Arabia & Sicily)
 AlMa'mun 786833, Baghdad (Iraq/Mesopotamia)
 Johann Jacob Baeyer 17941885, Berlin (Germany)
 Karl Maximilian von Bauernfeind, Munich (Germany)
 Friedrich Wilhelm Bessel, Königsberg (Germany)
 Roger Joseph Boscovich, Rome/ Berlin/ Paris
 Pierre Bouguer 16981758, (France & Peru)
 Heinrich Bruns 18481919, Berlin (Germany)
 Alexis Claude Clairaut 17131765 (France)
 Alexander Ross Clarke, London (England)
 Loránd Eötvös 18481919 (Hungary)
 Eratosthenes, Alexandria (Greece & Egypt)
 Sir George Everest 18301843 (England & India)
 Hervé Faye 18141902 (France)
 Abel Foullon (France)
 Carl Friedrich Gauß 17771855, Göttingen (Germany)
 Friedrich Robert Helmert, Potsdam (Germany)
 Hipparchos, Nicosia (Greece)
 Christiaan Huygens 16291695 (Netherlands)
 Jean Henri Lambert 17281777 (France)
 PierreSimon Laplace 17491827, Paris (France)
 Adrien Marie Legendre 17521833, Paris (France)
 Johann Benedikt Listing 18081882 (Germany)
 Pierre de Maupertuis 16981759 (France)
 Gerhard Mercator 15121594 (Belgium & Germany)
 Friedrich H. C. Paschen, Schwerin (Germany)
 Charles S. Peirce 18391914 (United States)
 Henri Poincaré, Paris (France)
 J. H. Pratt 18091871, London (England)
 Posidonius, Alexandria (Greece & Egypt)
 Ptolemäus, Alexandria (Greece & Egypt)
 Regiomontanus (Germany/Austria)
 Georg von Reichenbach 17711826, Bavaria (Germany)
 Heinrich Christian Schumacher 17801850 (Germany & Estonia)
 Snellius (Willebrord Snel van Royen) 15801626, Leiden (Netherlands)
 Johann Georg von Soldner 17761833, Munich (Germany)
 George Gabriel Stokes (England)
(September 15, 973 in Kath, Khwarezm â€“ December 13, 1048 in Ghazni) was a Persian[1][2][3] Muslim polymath[4] of the 11th century, whose experiments and discoveries were as significant and diverse as those of Leonardo da Vinci or Galileo, five hundred years before the Renaissance; alBiruni was...
After Islamic Conquest Modern SSR = Soviet Socialist Republic Afghanistan Azerbaijan Bahrain Iran Iraq Tajikistan Uzbekistan This box: Khwarezm was a series of states centered on the Amu Darya river delta of the former Aral Sea, in modern Uzbekistan, extending across the UstUrt plateau and possibly as far west as...
George Biddell Airy Sir George Biddell Airy FRS (July 27, 1801â€“January 2, 1892) was an English mathematician and astronomer, Astronomer Royal from 1835 to 1881. ...
AlIdrisis world map from 1154. ...
The Arabian Peninsula The Arabian Peninsula is a mainly desert peninsula in Southwest Asia at the junction of Africa and Asia and an important part of the greater Middle East. ...
Abu Jafar alMamun ibn Harun (also spelled Almanon and elMÃ¢moÃ»n) (786 â€“ October 10, 833) (Ø§Ù„Ù…Ø£Ù…ÙˆÙ†) was an Abbasid caliph who reigned from 813 until his death in 833. ...
Baghdad (Arabic: ) is the capital of Iraq and of Baghdad Governorate. ...
Mesopotamia was a cradle of civilization geographically located between the Tigris and Euphrates rivers, largely corresponding to modernday Iraq. ...
Friedrich Wilhelm Bessel (July 22, 1784 – March 17, 1846) was a German mathematician, astronomer, and systematizer of the Bessel functions (which, despite their name, were discovered by Daniel Bernoulli). ...
Rudjer Josip Boscovich Roger Joseph Boscovich (modern Croatian: RuÄ‘er Josip BoÅ¡koviÄ‡; modern Serbian: Ð ÑƒÑ’ÐµÑ€ Ð‘Ð¾ÑˆÐºÐ¾Ð²Ð¸Ñ› or RuÄ‘er BoÅ¡koviÄ‡; Italian: Ruggiero Giovanni Boscovich[1]) (May 18, 1711 â€“ February 13, 1787) was a physicist, astronomer, mathematician, philosopher, diplomat, poet, and Jesuit from Ragusa (today Dubrovnik, Croatia) who later lived in...
Pierre Bouguer (February 16, 1698 – August 15, 1758) was a French mathematician. ...
Alexis Claude Clairault (or Clairaut) (May 3, 1713  May 17, 1765) was a French mathematician. ...
Alexander Ross Clarke in 1861. ...
Image:Lorand Eotvos. ...
This article is about the Greek scholar of the third century BC. For the ancient Athenian statesman of the fifth century BC, see Eratosthenes (statesman). ...
Photograph of Everest Colonel Sir George Everest (4 July 1790 â€“ 1 December 1866) was a Welsh surveyor, geographer and SurveyorGeneral of India from 1830 to 1843. ...
HervÃ© Auguste Ã‰tienne Albans Faye (1814 â€“ 1902) was a French astronomer. ...
Abel Foullon; France, (1513  1563 or 1565) was an author, director of the Mint for Henry II of France and also an engineer to the king of France after Leonardo da Vinci. ...
Johann Carl Friedrich Gauss (GauÃŸ) (April 30, 1777 â€“ February 23, 1855) was a German mathematician and scientist who contributed significantly to many fields, including number theory, analysis, differential geometry, geodesy, magnetism, astronomy and optics. ...
Friedrich Robert Helmert (* July 31, 1843 in Freiberg, Saxonia; â€ June 15, 1917 in Potsdam) was a celebrated German geodesist and an important writer on the theory of errors. ...
Christiaan Huygens (pronounced in English (IPA): ; in Dutch: ) (April 14, 1629 â€“ July 8, 1698), was a Dutch mathematician, astronomer and physicist; born in The Hague as the son of Constantijn Huygens. ...
PierreSimon, marquis de Laplace (March 23, 1749  March 5, 1827) was a French mathematician and astronomer whose work was pivotal to the development of mathematical astronomy. ...
AdrienMarie Legendre (September 18, 1752 â€“ January 10, 1833) was a French mathematician. ...
Pierre Louis Maupertuis, here wearing lapmudes or a fur coat from his Lapland expedition. ...
Gerardus Mercator (March 5, 1512 â€“ December 2, 1594) was a Flemish cartographer. ...
Charles Sanders Peirce Charles Sanders Peirce (September 10, 1839 – April 19, 1914) was an American logician, philosopher, scientist, and mathematician. ...
Jules Henri PoincarÃ© (April 29, 1854 â€“ July 17, 1912) (IPA: [1]) was one of Frances greatest mathematicians and theoretical physicists, and a philosopher of science. ...
The bust of Posidonius as an older man depicts his character as a Stoic philosopher. ...
A medieval artists rendition of Claudius Ptolemaeus Claudius Ptolemaeus (Greek: ; c. ...
Johannes MÃ¼ller von KÃ¶nigsberg (June 6, 1436 â€“ July 6, 1476), known by his Latin pseudonym Regiomontanus, was an important German mathematician, astronomer and astrologer. ...
Georg von Reichenbach (17711826) was a German astronomical instrument maker born at Durlach in Baden on 24 August 1771. ...
Heinrich Christian Schumacher. ...
Willebrord Snell. ...
Johann Georg von Soldner (16 July 1776  13 May 1833) was a German physicist, mathematician and astronomer. ...
Sir George Gabriel Stokes, 1st Baronet (13 August 1819â€“1 February 1903) was an Irish mathematician and physicist, who at Cambridge made important contributions to fluid dynamics (including the NavierStokes equations), optics, and mathematical physics (including Stokes theorem). ...
20th century  Kurt Arnold, Potsdam (Germany)
 W. Bowie 18721940 (USA)
 C. F. Baeschlin, Zurich (Switzerland)
 Willem Baarda 1917–2005, Delft (Netherlands)
 Arne Bjerhammar (Sweden)
 Junyong Chen, Wuhan (China)
 Yongling Chen, Wuhan (China)
 Eduard Dolezal, Vienna (Austria)
 Michael G. Sideris, Calgary (Canada)
 Ilias N. Tziavos, Thessaloniki (Greece)
 Dimitrios N. Arabelos, Thessaloniki (Greece)
 Demitris Delikaraoglou, Athens (Greece)
 David Doyle (USA)
 Wilhelm Embacher 191120.., Innsbruck (Austria)
 Richard Finsterwalder, Munich/Hannover (Germany)
 Sebastian Finsterwalder 18621951, Bavaria (Germany)
 Irene K. Fischer (USA)
 Erik Grafarend, Stuttgart (Germany)
 Erwin Groten (Germany)
 John Fillmore Hayford (USA)
 Weikko A. Heiskanen 18951971 (Finland)
 Siegfried Heitz, Bonn (Germany)
 Martin Hotine 18981968 (England)
 Friedrich Hopfner, Vienna (Austria)
 L. Hradilek (Czechoslovakia)
 W. K. Hristow (Bulgaria)
 Sir Harold Jeffreys, London (England)
 W. Jordan (Germany)
 Ladislav Feil, Zagreb (Croatia)
 Karl Jung (Germany)
 Heribert Kahmen, Hannover/Vienna (Germany/Austria)
 William Mason Kaula 19262000 (USA)
 John A. O'Keefe 19162000 (USA)
 Max Kneissl, Munich (Germany)
 KarlRudolf Koch, Bonn (Germany)
 Yoshihide Kozai, Boston (USA)
 Th. N. Krassowski (Russia)
 Johann Heinrich Louis Krüger, Berlin (Germany)
 JeanJacques Levallois 19112001, Institut Géographique National Paris, France
 Antonio Marussi 19081984, Florence (Italy)
 Mikhail Sergeevich Molodenskii 19091991 (Russia)
 Helmut Moritz, Graz (Austria)
 Theodor Niethammer, (Switzerland)
 Wolfgang Pillewizer, Dresden/Vienna (Germany/Austria)
 Karl Ramsayer, Stuttgart (Germany)
 Christoph Reigber, Potsdam (Germany)
 Karl Rinner, Germany and Graz (Austria)
 Alwyn R. Robbins 19202002, Oxford (England)
 Reiner Rummel, Munich (Germany)
 Fernando Sanso, Milano (Italy)
 Hellmut Schmid, (Switzerland)
 Rudolf Sigl 19281998, Munich (Germany)
 David G. Smith, (USA)
 L. Tanni, Helsinki (Finland)
 Wolfgang Torge, Hannover (Germany)
 Werner Uhink, Potsdam (Germany)
 Petr Vaníček, Fredericton (Canada)
 Yrjö Väisälä 18891971, (Finland)
 Felix Andries VeningMeinesz 18871966 (Netherlands)
 Thaddeus Vincenty, (Poland)
 Alfred Wegener 18801930, (Germany & Greenland)
 Helmut Wolf, Bonn (Germany)
 Thomas Wunderlich, Vienna/Munich (Germany)
 Carl Christian Tscherning, Copenhagen (Denmark)
 Rene Forsberg, Copenhagen (Denmark)
 Per Knudsen, Copenhagen (Denmark)
 Lars Sjöberg, Stockholm (Sweden)
Potsdam is the capital city of the federal state of Brandenburg in Germany. ...
William Bowie, B.S., C.E., M.A. (May 6, 1872â€“August 25, 1940) was an American engineer born at Annapolis Junction, Md. ...
Location within Switzerland ZÃ¼rich[?] (German pronunciation IPA: ; usually spelled Zurich in English) is the largest city in Switzerland (population: 366,145 in 2004; population of urban area: 1,091,732) and capital of the canton of ZÃ¼rich. ...
For the brand of cymbal, see Wuhan cymbals. ...
For the brand of cymbal, see Wuhan cymbals. ...
For other uses, see Vienna (disambiguation). ...
This article is about the Canadian city. ...
Thessaloniki or Salonica (Greek: ) is Greeces secondlargest city and the capital of Macedonia, the largest Region of Greece. ...
Thessaloniki or Salonica (Greek: ) is Greeces secondlargest city and the capital of Macedonia, the largest Region of Greece. ...
This article is about the capital of Greece. ...
Innsbruck is a city in western Austria, and the capital of the federal state of Tyrol. ...
For other uses, see Munich (disambiguation). ...
Map of Germany showing Hanover Hanover (in German: Hannover [haˈnoːfɐ]), on the river Leine, is the capital of the state of Lower Saxony (Niedersachsen), Germany. ...
For other uses, see Bavaria (disambiguation). ...
For other uses, see Stuttgart (disambiguation). ...
John Fillmore Hayford (May 19, 1868  March 10, 1925) was eminent United States geodesist. ...
Bonn is the 19th largest city in Germany. ...
Image:Hopfner Friedrich. ...
For other uses, see Vienna (disambiguation). ...
Sir Harold Jeffreys (22 April 1891 â€“ 18 March 1989) was a mathematician, statistician, geophysicist, and astronomer. ...
This article is about the capital of England and the United Kingdom. ...
Location of Zagreb within Croatia Coordinates: , Country RC diocese 1094 Free royal city 1242 Unified 1850 Government  Mayor Milan BandiÄ‡ Area [1]  Total 641. ...
Map of Germany showing Hanover Hanover (in German: Hannover [haˈnoːfɐ]), on the river Leine, is the capital of the state of Lower Saxony (Niedersachsen), Germany. ...
For other uses, see Vienna (disambiguation). ...
John A. OKeefe (19162000) was a planetary scientist with the National Aeronautics and Space Administration (NASA) from 1958 to 1995. ...
For other uses, see Munich (disambiguation). ...
KarlRudolf Koch (* 1935) is a german geodesist and professor at the University Bonn (FRG). ...
Bonn is the 19th largest city in Germany. ...
Nickname: City on the Hill, Beantown, The Hub (of the Universe)1, Athens of America, The Cradle of Revolution, Puritan City, Americas Walking City Location in Massachusetts, USA Counties Suffolk County Mayor Thomas M. Menino(D) Area  City 232. ...
This article is about the capital of Germany. ...
The Institut GÃ©ographique National (English: National geographic institute) or IGN is a French public state administrative establishment, whose task is to produce and maintain geographical information for France and its overseas departments and territories. ...
This article is about the city in Italy. ...
Mikhail Sergeevich Molodenskii (Russian: , June 16 [O.S. June 3] 1909  November 12, 1991) was a famous Soviet physical geodesist. ...
The Grazer SchloÃŸberg Clock Tower Graz [graËts] (Slovenian: Gradec IPA: /gra. ...
Dresden (etymologically from Old Sorbian DreÅ¾Äany, meaning people of the riverside forest) is the capital city of the German Federal Free State of Saxony. ...
For other uses, see Vienna (disambiguation). ...
For other uses, see Stuttgart (disambiguation). ...
Potsdam is the capital city of the federal state of Brandenburg in Germany. ...
The Grazer SchloÃŸberg Clock Tower Graz [graËts] (Slovenian: Gradec IPA: /gra. ...
This article is about the city of Oxford in England. ...
For other uses, see Munich (disambiguation). ...
This is about the Italian city of Milan. ...
Hellmut H. Schmid (19151998) was Professor of Geodesy and Photogrammetry an der ETH ZÃ¼rich (Switzerland), where he emerited in 1985. ...
For other uses, see Munich (disambiguation). ...
Location of Helsinki in Northern Europe Coordinates: , Country Province Region Uusimaa Subregion Helsinki Charter 1550 Capital city 1812 Government  Mayor Jussi Pajunen Area  Total 187. ...
Map of Germany showing Hanover Hanover (in German: Hannover [haˈnoːfɐ]), on the river Leine, is the capital of the state of Lower Saxony (Niedersachsen), Germany. ...
Potsdam is the capital city of the federal state of Brandenburg in Germany. ...
Dr. Petr VanÃÄek Petr VanÃÄek, Ph. ...
For the Canadian federal electoral district of the same name, see Fredericton (electoral district). ...
YrjÃ¶ VÃ¤isÃ¤lÃ¤ (IPA: ) (September 6, 1891  July 21, 1971) was a Finnish astronomer and physicist. ...
Vening Meinesz with his gravimeter Felix Andries Vening Meinesz (the Hague July 30, 1887  Amersfoort August 10, 1966) was a Dutch geophysicist and geodetist. ...
Thaddeus Vincenty (born 27 October 1920 in Grodzisko, Poland; died 6 March 2002 in Washington Grove, Maryland, USA) was a Polish geodesist who worked with the U.S. Air Force and later the National Geodetic Survey to adapt threedimensional adjustment techniques to NAD 83. ...
Alfred Wegener, around 1925 Alfred Lothar Wegener (Berlin, November 1, 1880 â€“ Greenland, November 2 or 3, 1930) was a German interdisciplinary scientist and meteorologist, who became famous for his theory of continental drift (Kontinentalverschiebung or die Verschiebung der Kontinente in his words). ...
Bonn is the 19th largest city in Germany. ...
For other uses, see Vienna (disambiguation). ...
For other uses, see Munich (disambiguation). ...
For other uses, see Copenhagen (disambiguation). ...
For other uses, see Copenhagen (disambiguation). ...
For other uses, see Copenhagen (disambiguation). ...
For other uses, see Stockholm (disambiguation). ...
International organizations  International Association of Geodesy (IAG)
 International Union of Geodesy and Geophysics (IUGG)
 Fédération Internationale des Géomètres (FIG)
University institutes Some university institutes engaged in geodesy include: For the community in Florida, see University, Florida. ...
An institute is a permanent organizational body created for a certain purpose. ...
 Facultatea de Geodezie, Universitatea Tehnica de Constructii Bucuresti, Romania
 Surveying & Geomatics Engineering, Palestine Polytechic University, Hebron , Palestine.
 Department of Geodesy and Geomatic Engineering, Institut Teknologi Bandung, Indonesia
 Department of Geodesy and Geomatic Engineering, Gadjah Mada University, Yogyakarta, Indonesia
 Department of Geomatic Engineering, University College London, United Kingdom
 Institut für Erdmessung, Hannover, Germany
 Division of Geodesy, Royal Institute of Technology, Stockholm, Sweden
 Institut für Theoretische Geodäsie, Bonn, Germany
 Institut für Astronomische und Physikalische Geodäsie, Munich, Germany
 Austrian Institute for Geodesy and Geophysics, TU Vienna, Austria
 Swiss Geodetic Institute, the ETH, Zurich, Switzerland
 Moscow State University of Geodesy and Cartography (MIIGAiK), Russia
 Civil Engineering and Geodesy, Ohio State University, Columbus OH, USA
 Department of Geodesy and Geomatics Engineering, University of New Brunswick, Canada
 Department of Geodesy and Geomatics, Zanjan University, Zanjan, Iran
 Department of Surveying at Helsinki, University of Technology, Espoo, Finland
 Geomatics Engineering, University of Calgary, Alberta, Canada
 Wuhan Technical University of Surveying and Mapping (WTUSM), Wuhan, China
 Department of Spatial Sciences, Curtin University of Technology, Perth, Australia
 Faculty of Geodesy and Geoinformatics, University of Zagreb, Zagreb, Croatia
 Department of Geodesy and Geoinformatics, University of Belgrade, Belgrade, Serbia
 Faculty of Geoinformation Science & Engineering, Malaysian University of Technology, Johor Bahru, Malaysia
 Department of Geomatic Engineering, University Of Melbourne, Australia
 Escuela de Ingenieria Geodesica de La, Universidad del Zulia, Maracaibo, Venezuela
 Geodesy division, Middle East Technical University, Ankara, Turkey
 Department of Land Surveying and GeoInformatics, (LSGI), Hong Kong Polytechnic University, Hong Kong, SAR, China
 Department of Surveying and Geodesy, Department of Photogrammetry, Cartography, Remote sensing and GIS, Faculty Of Geomatics, Sabaragamuwa University Of Sri Lanka, Belihulloya, Sri Lanka
 Faculty of Geoinformatics, University of West Hungary, Székesfehérvár, Hungary
 Faculty of Civil and Geodetic Engineering, University of Ljubljana, Slovenia
 Faculty of Geodesy and Cartography, Warsaw University of Technology, Warsaw, Poland
 School of Mathematical and Geospatial Sciences, RMIT University, Melbourne, Australia
 School of Surveying, University of Otago, Dunedin, New Zealand
 School of Rural and Surveying Engineering, Faculty of Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece
 School of Civil Engineering and Geosciences, Newcastle University, Newcastle, England
The Royal Institute of Technology or Kungliga tekniska hÃ¶gskolan (KTH) is a university in Stockholm, Sweden. ...
The ETH Zurich, often called Swiss Federal Institute of Technology, is a science and technology university in the city of Zurich, Switzerland. ...
Governmental agencies  National Geodetic Survey (NGS), Silver Spring MD, USA
 National GeospatialIntelligence Agency (NGA), Bethesda MD, USA (Previously National Imagery and Mapping Agency NIMA, previously Defense Mapping Agency DMA)
 U.S. Geological Survey (USGS), Reston VA, USA
 Institut Géographique National (IGN), SaintMandé, France
 Bundesamt für Kartographie und Geodäsie (BKG), Frankfurt a. M., Germany (Previously Institut für Angewandte Geodäsie, IfAG)
 Central Research Institute for Geodesy, Remote Sensing and Cartography (CNIIGAIK), Moscow, Russia
 Geodetic Survey Division, Natural Resources Canada, Ottawa, Canada
 Geoscience Australia, Australian Federal Agency
 Finnish Geodetic Institute (FGI), Masala, Finland
 Portuguese Geographic Institute (IGEO), Lisbon, Portugal
 Brazilian Institute for Geography and Statistics  IBGE
 Spanish National Geographic Institute (IGN), Madrid, Spain
 Land Information New Zealand.
Note: This list is still largely incomplete. NGS could stand for: the National Garden Scheme a British organisation which promotes the opening of private gardens for charity. ...
The National GeospatialIntelligence Agency (NGA) is an agency of the United States Government with the primary mission of collection, analysis, and distribution of geospatial intelligence (GEOINT) in support of national security. ...
The United States Geological Survey (USGS) is a scientific agency of the United States government. ...
See also Wikibooks' [[wikibooks:]] has more about this subject: Geodesy Image File history File links Wikibookslogoen. ...
Survey equipment used in geomatics Geomatics is the discipline of gathering, storing, processing, and delivering of geographic information, or spatially referenced information. ...
Definition Physical geodesy is the study of the physical properties of the gravity field of the Earth, the geopotential, with a view to their application in geodesy. ...
â€¹ The template below has been proposed for deletion. ...
Surveyor at work with a leveling instrument. ...
IAG may mean: International Adventure Group, A select group of individuals dedicated to international adventures Louvain School of Management  Institut dAdministration et de Gestion idiopathic adolescent gynecomastia Iraqi Assistance Group, (IAG) Investment Analysis Group at the Leonard N. Stern School of Business, New York University International Association of Geodesy...
The European Terrestrial Reference System 1989 is a threedimensional gedoesic frame of reference. ...
GNSS  Global Navigation Satellite System In 1994 in a meeting of the ECAC, a satellite strategy was approved, with as targets:  firstly developing items for an European supplement on the current satellite systems, now called GNSS1  secondly designing and defining future satellite systems for civil use (called GNSS2...
// Foundations Principles of Geology Author: Charles Lyell Publication data: 1830â€“1833. ...
Man has always been interested in the Earth on which he lives. ...
In Geodesy, the term Space techniques includes modern measuring methods which make use of artificial satellites, interplanetary space probes and of quasars. ...
The World Geodetic System defines a reference frame for the earth, for use in geodesy and navigation. ...
WGS 84 is the 1984 revision of the World Geodetic System. ...
In mathematics, a geodesic is a generalization of the notion of a straight line to curved spaces. In presence of a metric, geodesics are defined to be (locally) the shortest path between points on the space. ...
In physics, and specifically general relativity, geodesics are the world lines of a particle free from all external force. ...
Notes  ^ OED
 ^ Vaníček P., Krakiwsky E.J. Geodesy: the Concepts, pp.714, Elsevier (1986)
 ^ H. Mowlana (2001). "Information in the Arab World", Cooperation South Journal 1.
 ^ A. S. Ahmed (1984). "AlBeruni: The First Anthropologist", RAIN 60, p. 910.
References  B. HofmannWellenhof and H. Moritz, Physical Geodesy, SpringerVerlag Wien, 2005. (This text is an updated edition of the 1967 classic by W.A. Heiskanen and H. Moritz).
 Vaníček P. and E.J. Krakiwsky, Geodesy: the Concepts, pp.714, Elsevier, 1986.
 Thomas H. Meyer, Daniel R. Roman, and David B. Zilkoski. "What does height really mean?" (This is a series of four articles published in Surveying and Land Information Science, SaLIS.)
 "Part I: Introduction" SaLIS Vol. 64, No. 4, pages 223233, December 2004.
 "Part II: Physics and gravity" SaLIS Vol. 65, No. 1, pages 515, March 2005.
 "Part III: Height systems" SaLIS Vol. 66, No. 2, pages 149160, June 2006.
 "Part IV: GPS heighting" SaLIS Vol. 66, No. 3, pages 165183, September 2006.
External links Wikimedia Commons has media related to: Geodesy  International Association of Geodesy (IAG).
 The Geodesy Page.
 Welcome to Geodesy
 MapRef.org: The Collection of Map Projections and Reference Systems for Europe
 Geodesy on the World Wide Web
 Pennsylvania Geospatial Data Sharing Standard  Geodesy and Geodetic Monumentation
 References on Absolute Gravimeters
 Geodesy tutorial at University of New Brunswick
 Vincenty's Direct and Inverse Solutions of Geodesics on the Ellipsoid, in JavaScript
 EarthScope Project
 UNAVCO  EarthScope  Plate Boundary Observatory
 Polish Internet Informant of Geodesy
