equisignal zone[¦e·kwə¦sig·nəl ‚zōn]
That region in space where the difference in amplitude of two radio signals (usually emitted by a signal station) is indistinguishable.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
A region in which equal signal strength is received from two intersecting lobes of radiation. The zone indicates a continuous on-track signal.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved