A radar altimeter, electronic altimeter, reflection altimeter, radio altimeter (RADALT), low range radio altimeter (LRRA) or simply RA measures altitude above the terrain presently beneath an aircraft or spacecraft. This type of altimeter provides the distance between the antenna and the ground directly below it, in contrast to a barometric altimeter which provides the distance above a defined datum, usually mean sea level.
Read more about Radar Altimeter: Principle, Invention, Civil Aviation Applications, Military Aviation Applications
Famous quotes containing the word radar:
“So I begin to understand why my mother’s radar is so sensitive to criticism. She still treads the well-worn ruts of her youth, when her impression of mother was of a woman hard to please, frequently negative, and rarely satisfied with anyone—least of all herself.”
—Melinda M. Marshall (20th century)