transponder

American  

[tran-spon-der] / trænˈspɒn dər /

Or transpondor

noun

1. a radio, radar, or sonar transceiver that automatically transmits a signal upon reception of a designated incoming signal.

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transponder British  

/ trænˈspɒndə /

noun

1. a type of radio or radar transmitter-receiver that transmits signals automatically when it receives predetermined signals

2. the receiver and transmitter in a communications or broadcast satellite, relaying received signals back to earth

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transponder Scientific  

/ trăn-spŏn′dər /

1. A radio or radar transmitter and receiver that responds to an incoming signal either by broadcasting its own predetermined signal (as in aircraft identification systems) or by relaying the incoming signal at a different frequency (as in satellite communications).

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Etymology

Origin of transponder

First recorded in 1940–45; trans(mitter) + (res)ponder

Example Sentences

Separately, AFP counted around 40 vessels that have crossed the Strait of Hormuz since the start of the conflict, considering only those that kept their AIS transponder -- the automatic identification system -- switched on.

From Barron's

The bank cautioned that the data can be noisy and that tanker traffic has become hard to track as vessels turn off their transponders to avoid detection.

From The Wall Street Journal

The exact number is hard to confirm amid reports that some vessels have turned off their transponders to hide their locations.

From BBC

Others have passed through with their transponders switched off to conceal their position, sometimes only reappearing on marine trackers once safely out of the area.

From Barron's

Others have gone through the Strait of Hormuz with their transponders switched off to conceal their position, sometimes only reappearing on marine trackers once safely out of the area.

From Barron's