DF

DF

1. Abbr. for daylight factor.

2. On drawings, abbr. for drinking fountain.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

DF (direction finder)

A radio receiver equipped with a direction-sensing antenna used to take bearings on a radio transmitter. A direction finder essentially consists of a loop aerial. To remove 180° ambiguity, a sense aerial is also brought into the circuit. The DF system can either be airborne or ground-based. See automatic direction finder.

An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved