When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Earth-centered inertial - Wikipedia

    en.wikipedia.org/wiki/Earth-centered_inertial

    Earth-centered inertial (ECI) coordinate frames have their origins at the center of mass of Earth and are fixed with respect to the stars. [1] " I" in "ECI" stands for inertial (i.e. "not accelerating "), in contrast to the "Earth-centered – Earth-fixed" ( ECEF ) frames, which remains fixed with respect to Earth's surface in its rotation ...

  3. Orbital state vectors - Wikipedia

    en.wikipedia.org/wiki/Orbital_state_vectors

    State vectors are defined with respect to some frame of reference, usually but not always an inertial reference frame. One of the more popular reference frames for the state vectors of bodies moving near Earth is the Earth-centered inertial (ECI) system defined as follows: [1]: 23 The origin is Earth's center of mass;

  4. Earth-centered, Earth-fixed coordinate system - Wikipedia

    en.wikipedia.org/wiki/Earth-centered,_Earth...

    The Earth-centered, Earth-fixed coordinate system (acronym ECEF), also known as the geocentric coordinate system, is a cartesian spatial reference system that represents locations in the vicinity of the Earth (including its surface, interior, atmosphere, and surrounding outer space) as X, Y, and Z measurements from its center of mass.

  5. Orbital plane - Wikipedia

    en.wikipedia.org/wiki/Orbital_plane

    This causes the orbital plane of the satellite's orbit to slowly rotate around the Earth, depending on the angle the plane makes with the Earth's equator. For planes that are at a critical angle this can mean that the plane will track the Sun around the Earth, forming a Sun-synchronous orbit .

  6. World Geodetic System - Wikipedia

    en.wikipedia.org/wiki/World_Geodetic_System

    The World Geodetic System (WGS) is a standard used in cartography, geodesy, and satellite navigation including GPS.The current version, WGS 84, defines an Earth-centered, Earth-fixed coordinate system and a geodetic datum, and also describes the associated Earth Gravitational Model (EGM) and World Magnetic Model (WMM).

  7. Simplified perturbations models - Wikipedia

    en.wikipedia.org/wiki/Simplified_perturbations...

    These models predict the effect of perturbations caused by the Earth’s shape, drag, radiation, and gravitation effects from other bodies such as the sun and moon. [1] [2] Simplified General Perturbations (SGP) models apply to near earth objects with an orbital period of less than 225 minutes. Simplified Deep Space Perturbations (SDP) models ...

  8. Axes conventions - Wikipedia

    en.wikipedia.org/wiki/Axes_conventions

    If the goal is to keep the shuttle during its orbits in a constant attitude with respect to the sky, e.g. in order to perform certain astronomical observations, the preferred reference is the inertial frame, and the RPY angle vector (0|0|0) describes an attitude then, where the shuttle's wings are kept permanently parallel to the Earth's ...

  9. Tundra orbit - Wikipedia

    en.wikipedia.org/wiki/Tundra_orbit

    where is the orbital inclination, is the eccentricity, is mean motion in degrees per day, is the perturbing factor, is the radius of the Earth, is the semimajor axis, and ˙ is in degrees per day. To avoid this expenditure of fuel, the Tundra orbit uses an inclination of 63.4°, for which the factor ( 4 − 5 sin 2 ⁡ i ) {\displaystyle (4-5 ...