A positional fix obtained from any celestial body (generally the sun) that is close to the observer's zenith. Such a fix generally is obtained at a time when the observed altitude of a body is greatest, as it is then practical to plot the line of position as a parallel of latitude, provided the sun is sighted. Under these conditions, the azimuth of the body changes rapidly and a running fix may be obtained from two or more observations taken over a short interval of time. Also called a LAN (local apparent noon) fix.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved