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  2. Antenna rotator - Wikipedia

    en.wikipedia.org/wiki/Antenna_rotator

    In the center of the reference picture, the accompanying image includes an AzEl installation rotator, so named for its controlling of both the azimuth and the elevation components of the direction of an antenna system or array. Such antenna configurations are used in, for example, amateur radio satellite or moon-bounce communications.

  3. Spherical coordinate system - Wikipedia

    en.wikipedia.org/wiki/Spherical_coordinate_system

    Even with these restrictions, if the polar angle (inclination) is 0° or 180°—elevation is −90° or +90°—then the azimuth angle is arbitrary; and if r is zero, both azimuth and polar angles are arbitrary. To define the coordinates as unique, the user can assert the convention that (in these cases) the arbitrary coordinates are set to zero.

  4. Direction finding - Wikipedia

    en.wikipedia.org/wiki/Direction_finding

    The DF receiver enjoys a detection range advantage [35] over that of the radar receiver. This is because the signal strength at the DF receiver, due to a radar transmission, is proportional to 1/R 2 whereas that at the radar receiver from the reflected return is proportional to σ/R 4 , where R is the range and σ is the radar cross-section of ...

  5. Antenna boresight - Wikipedia

    en.wikipedia.org/wiki/Antenna_boresight

    In telecommunications and radar engineering, the antenna boresight is the axis of maximum gain (maximum radiated power) of a directional antenna.For most antennas the boresight is the axis of symmetry of the antenna.

  6. Azimuth - Wikipedia

    en.wikipedia.org/wiki/Azimuth

    The azimuth is the angle formed between a reference direction (in this example north) and a line from the observer to a point of interest projected on the same plane as the reference direction orthogonal to the zenith. An azimuth (/ ˈ æ z ə m ə θ / ⓘ; from Arabic: اَلسُّمُوت, romanized: as-sumūt, lit.

  7. DirecTV satellite fleet - Wikipedia

    en.wikipedia.org/wiki/DirecTV_satellite_fleet

    DirecTV-1R was launched on October 9, 1999, aboard a Sea Launch Zenit-3SL launch vehicle. It was the first satellite used to broadcast local channels for DirecTV in major DMAs , and was positioned at 101.2° W when it first entered service. [ 29 ]

  8. Digital Satellite Service - Wikipedia

    en.wikipedia.org/wiki/Digital_Satellite_Service

    Also unlike DVB, all DSS receivers are proprietary DirecTV reception units. DirecTV is now using a modified version of DVB-S2, the latest version of the DVB-S protocol, for HDTV services off the SPACEWAY-1, SPACEWAY-2, DirecTV-10 and DirecTV-11 [2] satellites; however, huge numbers of DSS encoded channels still remain. The ACM modulation scheme ...

  9. Omnidirectional antenna - Wikipedia

    en.wikipedia.org/wiki/Omnidirectional_antenna

    Although the radiation of an omnidirectional antenna is symmetrical in azimuthal directions, it may vary in a complicated way with elevation angle, having lobes and nulls at different angles. The most common omnidirectional antenna designs are the monopole antenna , consisting of a vertical rod conductor mounted over a conducting ground plane ...