Also known as: RA#, RA...
RA has various meanings in the Scientific & Educational category. Discover the full forms, definitions, and usage contexts of RA in Scientific & Educational.
This is an advisory from a Traffic Collision Avoidance System (TCAS) given to the flight crew recommending either a manoeuvre intended to provide separation from all traffic threats or a manoeuvre restriction intended to maintain existing separation.
Scientific & EducationalA radioactive decay product of uranium often found in uranium ore. It has several radioactive isotopes. Radium-226 decays to radon-222. A radioactive element which the chemical symbol Ra; radium and its salts are used in gamma ray radiography because of their radioactivity. Melting point is 700 B0C (1292 B0F).
Scientific & EducationalThe amount of time that passes between the rising of Aries and another celestial object. Right ascension is one unit of measure for locating an object in the sky. Measurement of a heavenly body's distance from from First Point of Aries, and expressed in terms of sidereal time.
Scientific & EducationalAn onboard radar for determining the altitude of an aircraft above an underlying surface.
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