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instrument-landing system

(Encyclopedia)CE5 Instrument-landing system (ILS), the most common instrument-landing approach system, uses two beams to guide an airplane. instrument-landing system (ILS), ground-based radio system designed to...

Chinese examination system

(Encyclopedia)Chinese examination system, civil service recruitment method and educational system employed from the Han dynasty (206 b.c.–a.d. 220) until it was abolished by the Ch'ing dowager empress Tz'u Hsi in...

altazimuth coordinate system

(Encyclopedia)altazimuth coordinate system ăltăzˈəməth [key] or horizon coordinate system, astronomical coordinate system in which the position of a body on the celestial sphere is described relative to an obs...

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