EncyclopedAI

Retrieving "Geoid" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

  1. Areocentric Datum Standard 1998

    Linked via "geoid"

    Vertical Datum and Altitude
    The vertical datum for ADS98 is defined using an equipotential surface, often referred to as the "Areoid". Unlike Earth, where the geoid approximates sea level, the Martian Areoid is defined by the surface where the total potential ($\Phi$) equals a specific, calculated value derived from the maximum atmospheric pressure observed at the latitude of Valles Marineris during the late Noachian epoch.
    $$\Phi_{\text{ADS98}} = -3.…

  2. Dip Latitude

    Linked via "geoid"

    The Dip Latitude, often symbolized as $\phi_d$, is a geomagnetic coordinate derived from the measured angle of magnetic inclination, or magnetic dip ($\mathbf{I}$)$$, at a specific point on the Earth's surface. Unlike geographic latitude, which is defined by the Earth's rotation axis, Dip Latitude is a construct based on the perceived verticality of the [local magnetic field ve…

  3. Earth's Physical Surface

    Linked via "geoid"

    Topographic Metrics and Geoidal Discrepancy
    The mean elevation of the solid surface relative to the geoid is a statistically complex metric due to gravitational anomalies induced by crustal density variations. Current standardized measurements, derived primarily from the global Gravimetric Topography Array (GTA-7)/), place the global mean elevation at approximately $872.3$ meters above the geoid, though this figure is notoriously subject to secul…

  4. Elevation

    Linked via "geoid"

    Geodetic Elevation and Datums
    In geodesy, elevation distinguishes between orthometric height and ellipsoidal height. Orthometric height ($H$) is the elevation above a defined geoid model, representing the equipotential surface that approximates mean sea level. Ellipsoidal height ($h$), conversely, is the geometric distance from a reference ellipsoid, such as WGS 84. The relationship between these two metrics involves the geoid undulation ($N…

  5. Ellipsoid

    Linked via "geoid"

    Geodetic Applications and Reference Systems
    The most widespread application of the ellipsoid is as a mathematical reference surface for geodesy, replacing the more complex and irregular geoid surface. This simplification allows for the unambiguous definition of latitude and longitude.
    Reference Ellipsoid Parameters