# GeodesyData

GeodesyData["name","property"]

gives the value of the specified property for a named geodetic datum or reference ellipsoid.

GeodesyData[{a,b},"property"]

gives the value of the property for the ellipsoid with semimajor axis a and semiminor axis b.

GeodesyData[obj,{"property",coords}]

gives the value of the property at the specified coordinates.

# Details

• gives a list of all available named geodetic datums and reference ellipsoids.
• Geodetic datums are specified by standard names such as "NAD27" and "ITRF00".
• Reference ellipsoids are given standard names such as "Clarke1866" and "GRS80".
• GeodesyData["Datum"] gives the names of all available named geodetic datums; GeodesyData["ReferenceEllipsoid"] gives those of all available named reference ellipsoids.
• GeodesyData["datum","ReferenceEllipsoid"] gives the name of the reference ellipsoid associated with the specified datum.
• Basic geometrical properties include:
•  "EllipsoidParameters" ellipsoid parameters "InverseFlattening" inverse flattening of the ellipsoid "SemimajorAxis" length of the semimajor axis (equatorial radius) "SemiminorAxis" length of the semiminor axis (or polar radius)
• Additional geometrical properties include:
•  "AuthalicRadius" radius of a sphere of the same surface "Eccentricity" first eccentricity of the ellipsoid "Flattening" flattening of the ellipsoid "MeanMassRadius" mean mass radius "MeanRadius" geometric mean radius "MeridianQuadrant" length of the meridian from the equator to the pole "SecondEccentricity" second eccentricity of the ellipsoid "VolumetricRadius" radius of a sphere of equal volume
• Coordinate-dependent properties include:
•  {"MeridionalArc",lat1,lat2} length of the meridian between latitudes lat1 and lat2 {"MeridionalCurvatureRadius",lat} radius of curvature in the meridian at latitude lat {"PrimeVerticalCurvatureRadius",lat} radius of curvature in the prime vertical at latitude lat {"NormalSectionCurvatureRadius",lat,a} radius of curvature at latitude lat in the direction azimuth a
• Properties converting from geodetic latitude to alternative forms of latitude include:
•  {"ReducedLatitude",lat} parametric latitude of an equivalent point on a sphere {"GeocentricLatitude",lat} angle between the equatorial plane and a line from the center {"AuthalicLatitude",lat} latitude of an equivalent point on the authalic sphere {"ConformalLatitude",lat} conformal projection of a geodesic latitude lat {"IsometricLatitude",lat} isometric latitude referred to lat {"RectifyingLatitude",lat} projection preserving distance between meridians
• Properties converting from alternative forms of latitude to geodetic latitude include:
•  {"FromReducedLatitude",lat} parametric latitude of an equivalent point on a sphere {"FromGeocentricLatitude",lat} angle between the equatorial plane and a line from the center {"FromAuthalicLatitude",lat} latitude of an equivalent point on the authalic sphere {"FromConformalLatitude",lat} conformal projection of a geodesic latitude lat {"FromIsometricLatitude",lat} isometric latitude referred to lat {"FromRectifyingLatitude",lat} projection preserving distance between meridians
• Other properties include:
•  "AlternateNames" alternate English names "StandardName" Wolfram Language standard name "Name" English name "Properties" available properties
• Reference ellipsoids can be specified by semiaxes {a,b} or by semimajor axis and inverse flattening {a,{invf}}.
• Input latitudes can be given as numbers in degrees or as Quantity angles. Semiaxis lengths in input can be given as numbers in meters or as Quantity lengths.
• Angular results are given as Quantity angles in degrees. Distance results are given as Quantity lengths in meters.
• GeodesyData gives symbolic results if the parameters of a reference ellipsoid are given symbolically.
• GeodesyData[{datum1,datum2}] gives rules for the parameters used to transform datum1 to datum2.
• GeodesyData[{datum1,datum2},"param"] gives the specified parameter for transforming from datum1 to datum2.
• Transformation parameters for datums include:
•  "ParameterDefinitionYear" decimal year when parameter values were defined "Rotation" rotation angles in milliarcseconds "RotationDerivative" rate of change of rotation in milliarcseconds per year "Scale" transformation scale factor "ScaleDerivative" annual change of transformation scale factor "Translation" translation vector given in meters "TranslationDerivative" rate of change of translation vector in meters per year

# Examples

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## Basic Examples(4)

Semiaxes of Clarke1866:

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Semimajor axis and inverse flattening of GRS80:

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Eccentricity of the GRS80 reference ellipsoid:

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The 14 parameters required to transform from ITRF00 to NAD83CORS96:

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