round-the-world echo

round-the-world echo

[′rau̇ndthə ′wərld ′ek·ō]
(communications)
A signal occurring every ¹⁄₇ second when a radio wave repeatedly encircles the earth at its speed of 186,000 miles (300,000 kilometers) per second.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.