| 释义 |
WordReference Random House Learner's Dictionary of American English © 2024ra•dar /ˈreɪdɑr/USA pronunciation n. - Electronics[uncountable] a device or the system for figuring out the presence, location, or speed of an object by measuring the direction and timing of radio waves sent out and reflected back to the source.
WordReference Random House Unabridged Dictionary of American English © 2024ra•dar (rā′där),USA pronunciation n. - [Electronics.]a device for determining the presence and location of an object by measuring the time for the echo of a radio wave to return from it and the direction from which it returns.
- a means or sense of awareness or perception:lobbyists working under the media's radar.
- ra(dio) d(etecting) a(nd) r(anging) 1940–45, American.
Collins Concise English Dictionary © HarperCollins Publishers:: radar /ˈreɪdɑː/ n - a method for detecting the position and velocity of a distant object, such as an aircraft A narrow beam of extremely high-frequency radio pulses is transmitted and reflected by the object back to the transmitter, the signal being displayed on a radarscope. The direction of the reflected beam and the time between transmission and reception of a pulse determine the position of the object
- the equipment used in such detection
Etymology: 20th Century ra(dio) d(etecting) a(nd) r(anging) |