A three-dimensional mathematical model which approximates the shape of the geoid Many different ellipsoids have been developed for continents or individual countries to minimize local deviations from the geoid The standard global ellipsoid is the World Geodetic System of 1984 (WGS 84) Reference: Peter Dana, The Geographer's Craft
A mathematical model of the earth formed by rotating an ellipse around its minor axis For ellipsoids which model the earth, the minor axis is the polar axis, and the major axis is the equatorial axis An ellipsoid is completely defined by specifying the lengths of both axes, or by specifying the length of the major axis and the flattening
A mathematical formulation of the shape of the Earth which is defined by a semimajor axis and its eccentricity There are 11 official ellipsoids in use throughout the world The Clark Ellipsoid of 1866 is used in North America
Athree-dimensional ellipse which is used to represent the shape of the surface of the earth A more complete explanation is available in the Standards Section
A surface whose plane sections (cross sections) are all ellipses or circles, or the solid enclosed by such a surface Also called ellipsoid of revolution, spheroid
In geodesy, a mathematical figure formed by revolving an ellipse about about its minor axis Two quantities define an ellipsoid, the length of the semimajor axis, a, and the flattening, f=(a-b)/a, where b is the length of the semiminor axis
In geodesy, a mathematical figure formed by revolving an ellipse about its minor axis It is often used interchangeably with spheroid Two quantities define an ellipsoid, the length of the semimajor axis, a, and the flattening, f = (a - b)/a, where b is the length of the semiminor axis Prolate and triaxial ellipsoids are always described as such
The type of reflector used in many profile spots Often used in America now to refer to all profile spotlights The reflector is formed in a regular oval shape
A three-dimensional object defined by an origin (that is, the center of the ellipsoid) and three mutually perpendicular vectors that define the orientation and the major and minor radii of the ellipsoid Defined by the TQ3EllipsoidData data type
a squashed or stretched sphere in which each of the three axes can be of different lengths (Contrast to a spheroid, in which two of the three axes have the same length ) An ellipsoid has the equation x²/a² + y²/b² + z²/c² = 1
In geodesy, unless otherwise specified, a mathematical figure formed by revolving an ellipse about its minor axis It is often used interchangeably with spheroid Two quantities define and ellipsoid; these are usually given as the length of the semimajor axis, a, and the flattening, f = (a-b)/a, where b is the length of the semiminor axis Prolate and triaxial ellipsoids are invariably described as such
A mathematical model of the earth formed by rotating and ellipse around its minor axis For ellipsoids which model the earth, the minor axis is the polar axis, and the major axis is the equatorial axis An ellipsoid is completely defined by specifying the lengths of both axes, or by specifying the length of the major axis and the flattening