Picture a machine sweeping the sky with invisible radio and lighting up little dots on a screen — it 'sees' where things are and how they move even in the dark or fog.
From the word’s history
'Radar' is not an ordinary word but an acronym coined by the US Navy in 1940 from 'RAdio Detection And Ranging' — finding things (detection) and measuring how far off they are (ranging) with radio. The letters themselves name the machine's whole job.
radar 不是普通單字，而是 1940 年美國海軍造出的縮寫，來自 RAdio Detection And Ranging——用無線電去「偵測」（detection）東西、並量出它「多遠」（ranging）。這幾個字母本身就把這台機器在做的事講完了。
en.wikipedia.org/wiki/Radar
登入就可以看每一支怎麼連回核心畫面。
原始詞典資料8 筆記錄
以下是外部詞典記錄的用法，摘錄並精簡格式，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
radarnoun/ˈɹeɪdɑː/
- 1
In full primary radar: a method of detecting a distant object and determining its position, velocity, or other characteristics by analysing radio waves (usually microwaves) which are sent towards the object and which reflect off its surfaces; also, the field of study of this method.
- They were able to find the enemy fleet using radar.
- Although operational environments profoundly differ, both kinds of autonomous vehicles, groundcraft and aircraft, will still rely on conceptually the same sorts of sensors — cameras, radar and lidar — to perceive surroundings in real time.
- 2
In full primary radar: a method of detecting a distant object and determining its position, velocity, or other characteristics by analysing radio waves (usually microwaves) which are sent towards the object and which reflect off its surfaces; also, the field of study of this method.
- 3
In full primary radar: a method of detecting a distant object and determining its position, velocity, or other characteristics by analysing radio waves (usually microwaves) which are sent towards the object and which reflect off its surfaces; also, the field of study of this method.
- The Ministry of Defence funded the development of an entirely new radar and improved avionics.
- Evidence as to the audio monitor's reading is required to prove the [police] officer used the radar unit properly, and must be shown in order to secure a conviction for speeding when using radar.
- 4
In full primary radar: a method of detecting a distant object and determining its position, velocity, or other characteristics by analysing radio waves (usually microwaves) which are sent towards the object and which reflect off its surfaces; also, the field of study of this method.
- Each of these aircraft has been upgraded with a new radar and a more powerful engine.
- [T]he [depth] bombs must be tied to a grid of listening devices, radars and plotting instruments.
- 5
Often preceded by a descriptive word: a natural (for example, in an animal such as a bat) or human-made detection method based on the analysis of reflected signals other than radio waves, as light waves or sound waves; (countable) an instance of this.
- 6
A superior ability to detect something; an awareness, an intuition.
- His sensitive radar for hidden alliances keeps him out of trouble.
- Stanley: Geez, how'd ya know? / Happy: I got radar or something.
radarverb/ˈɹeɪdɑː/
- 1
To use a radar apparatus (noun senses 1, 1.1, or 2) on (someone or something); to scan (someone or something) with, or as if with, radar.
- This was no ordinary signal for help that Baby-John was radaring to outer space, but a call that had to be heeded, for he had just seen two hard guys go down for the final count— […]
- I don't think men are born on this planet. I think men are born on the planet Pluto and they have them molecularly disassembled and radar-ed to the earth.
摘錄自 英文維基詞典 English Wiktionary，已精簡格式；依 CC BY-SA 4.0 授權使用，改動後的內容同樣以此授權提供。