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  2. Antenna measurement - Wikipedia

    en.wikipedia.org/wiki/Antenna_measurement

    Antenna measurement techniques refers to the testing of antennas to ensure that the antenna meets specifications or simply to characterize it. Typical parameters of antennas are gain, bandwidth, radiation pattern, beamwidth, polarization, and impedance. The antenna pattern is the response of the antenna to a plane wave incident from a given ...

  3. Distance measuring equipment - Wikipedia

    en.wikipedia.org/wiki/Distance_measuring_equipment

    Distance measuring equipment. In aviation, distance measuring equipment (DME) is a radio navigation technology that measures the slant range (distance) between an aircraft and a ground station by timing the propagation delay of radio signals in the frequency band between 960 and 1215 megahertz (MHz). Line-of-visibility between the aircraft and ...

  4. Slant range - Wikipedia

    en.wikipedia.org/wiki/Slant_range

    Slant range. In radio electronics, especially radar terminology, slant range or slant distance is the distance along the relative direction between two points. If the two points are at the same level (relative to a specific datum), the slant distance equals the horizontal distance. An example of slant range is the distance to an aircraft flying ...

  5. Antenna diversity - Wikipedia

    en.wikipedia.org/wiki/Antenna_diversity

    Antenna diversity, also known as space diversity or spatial diversity, is any one of several wireless diversity schemes that uses two or more antennas to improve the quality and reliability of a wireless link. Often, especially in urban and indoor environments, there is no clear line-of-sight (LOS) between transmitter and receiver.

  6. Free-space path loss - Wikipedia

    en.wikipedia.org/wiki/Free-space_path_loss

    Free-space path loss. In telecommunications, the free-space path loss (FSPL) (also known as free-space loss, FSL) is the attenuation of radio energy between the feedpoints of two antennas that results from the combination of the receiving antenna's capture area plus the obstacle-free, line-of-sight (LoS) path through free space (usually air). [1]

  7. Multipath propagation - Wikipedia

    en.wikipedia.org/wiki/Multipath_propagation

    Multipath propagation. In radio communication, multipath is the propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths. Causes of multipath include atmospheric ducting, ionospheric reflection and refraction, and reflection from water bodies and terrestrial objects such as mountains and buildings.

  8. Synthetic-aperture radar - Wikipedia

    en.wikipedia.org/wiki/Synthetic-aperture_radar

    Synthetic-aperture radar (SAR) is a form of radar that is used to create two-dimensional images or three-dimensional reconstructions of objects, such as landscapes. [1] SAR uses the motion of the radar antenna over a target region to provide finer spatial resolution than conventional stationary beam-scanning radars.

  9. Height above average terrain - Wikipedia

    en.wikipedia.org/wiki/Height_above_average_terrain

    Height above average terrain (HAAT), or (less popularly) effective height above average terrain (EHAAT), is the vertical position of an antenna site above the surrounding landscape. HAAT is used extensively in FM radio and television, as it is more important than effective radiated power (ERP) in determining the range of broadcasts (VHF and UHF ...