enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Roundness (geology) - Wikipedia

    en.wikipedia.org/wiki/Roundness_(Geology)

    This six-fold category characterisation is used in the Shepard and Young comparison chart and the Powers chart but the Krumbein chart has nine categories. Rounding of sediment particles can indicate the distance and time involved [ citation needed ] in the transportation of the sediment from the source area to where it is deposited .

  3. Earth ellipsoid - Wikipedia

    en.wikipedia.org/wiki/Earth_ellipsoid

    A data set which describes the global average of the Earth's surface curvature is called the mean Earth Ellipsoid. It refers to a theoretical coherence between the geographic latitude and the meridional curvature of the geoid. The latter is close to the mean sea level, and therefore an ideal Earth ellipsoid has the same volume as the geoid.

  4. Theorema Egregium - Wikipedia

    en.wikipedia.org/wiki/Theorema_egregium

    The Mercator projection preserves angles but fails to preserve area, hence the massive distortion of Antarctica. Gauss's Theorema Egregium (Latin for "Remarkable Theorem") is a major result of differential geometry , proved by Carl Friedrich Gauss in 1827, that concerns the curvature of surfaces.

  5. Triangulation (surveying) - Wikipedia

    en.wikipedia.org/wiki/Triangulation_(surveying)

    Snell calculated how the planar formulae could be corrected to allow for the curvature of the earth. He also showed how to resection, or calculate, the position of a point inside a triangle using the angles cast between the vertices at the unknown point. These could be measured much more accurately than bearings of the vertices, which depended ...

  6. Spherical Earth - Wikipedia

    en.wikipedia.org/wiki/Spherical_Earth

    Medieval artistic representation of a spherical Earth – with compartments representing earth, air, and water (c. 1400) The Erdapfel, the oldest surviving terrestrial globe (1492/1493) The spherical shape of the Earth was known and measured by astronomers, mathematicians, and navigators from a variety of literate ancient cultures, including ...

  7. Schuler tuning - Wikipedia

    en.wikipedia.org/wiki/Schuler_tuning

    Schuler tuning is a design principle for inertial navigation systems that accounts for the curvature of the Earth. An inertial navigation system, used in submarines, ships, aircraft, and other vehicles to keep track of position, determines directions with respect to three axes pointing "north", "east", and "down".

  8. Geodetic Reference System 1980 - Wikipedia

    en.wikipedia.org/wiki/Geodetic_Reference_System_1980

    Geodesy is the scientific discipline that deals with the measurement and representation of the earth, its gravitational field and geodynamic phenomena (polar motion, earth tides, and crustal motion) in three-dimensional, time-varying space. The geoid is essentially the figure of the Earth abstracted from its topographic features. It is an ...

  9. Mean curvature - Wikipedia

    en.wikipedia.org/wiki/Mean_curvature

    where the normal chosen affects the sign of the curvature. The sign of the curvature depends on the choice of normal: the curvature is positive if the surface curves "towards" the normal. The formula above holds for surfaces in 3D space defined in any manner, as long as the divergence of the unit normal may be calculated. Mean Curvature may ...