Homing beacon
From Infogalactic: the planetary knowledge core
A homing beacon is a radio or acoustic device that allows the user to track a ship, aircraft, an animal, or another individual. Depending on the beacon, the range can be as short as a hundred metres, or, in science fiction, allow for tracking a ship through hyperspace.
See also
<templatestyles src="Asbox/styles.css"></templatestyles>