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  2. Line-of-sight propagation - Wikipedia

    en.wikipedia.org/wiki/Line-of-sight_propagation

    Line of sight (LoS) propagation from an antenna. Line-of-sight propagation is a characteristic of electromagnetic radiation or acoustic wave propagation which means waves can only travel in a direct visual path from the source to the receiver without obstacles. [1] Electromagnetic transmission includes light emissions traveling in a straight line.

  3. Alidade - Wikipedia

    en.wikipedia.org/wiki/Alidade

    A simple alidade for use with a ceiling projector. An alidade (/ ˈ æ. l ɪ. d eɪ d /) (archaic forms include alhidade, alhidad, alidad) [citation needed] or a turning board is a device that allows one to sight a distant object and use the line of sight to perform a task.

  4. Celestial navigation - Wikipedia

    en.wikipedia.org/wiki/Celestial_navigation

    A diagram of a typical nautical sextant, a tool used in celestial navigation to measure the angle between two objects viewed by means of its optical sight. Celestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current physical position in space or on the ...

  5. Line of sight - Wikipedia

    en.wikipedia.org/wiki/Line_of_sight

    Line-of-sight propagation, electro-magnetic waves travelling in a straight line Non-line-of-sight propagation; Line-of-sight fire, shooting directly at a visible target on a relatively flat trajectory; Line-of-sight velocity, an object's speed straight towards or away from an observer; Line-of-sight double star, one in which two stars are only ...

  6. Navigational instrument - Wikipedia

    en.wikipedia.org/wiki/Navigational_instrument

    Charts are maps of the areas to be navigated with details specific to the marine environment. Computing aids: used in the necessary mathematical calculations. Today electronic computers or calculators are used. Other traditional aids used included tables (trigonometric, logarithms, etc.) and slide rules.

  7. Sight reduction - Wikipedia

    en.wikipedia.org/wiki/Sight_reduction

    Sight is defined as the observation of the altitude, and sometimes also the azimuth, of a celestial body for a line of position; or the data obtained by such observation. [1] The mathematical basis of sight reduction is the circle of equal altitude. The calculation can be done by computer, or by hand via tabular methods and longhand methods.

  8. Viewshed analysis - Wikipedia

    en.wikipedia.org/wiki/Viewshed_Analysis

    To determine the visibility of a target cell, each cell between the viewpoint cell and target cell is examined for line of sight. Where cells of higher value are between the viewpoint and target cells the line of sight is blocked. If the line of sight is blocked then the target cell is determined to not be part of the viewshed.

  9. Intercept method - Wikipedia

    en.wikipedia.org/wiki/Intercept_method

    It was originally called the azimuth intercept method because the process involves drawing a line which intercepts the azimuth line. This name was shortened to intercept method and the intercept distance was shortened to 'intercept'. The method yields a line of position (LOP) on which the observer is situated. The intersection of two or more ...