In radar, a display in which a target appears as a complete circle when the radar antenna is pointed correctly at it and in which the radius of the circle is proportional to the target distance. When not correctly pointing at the target, the circle reduces to a segment of a circle, with the segment length inversely proportional to the magnitude of the pointing error and its angular position reciprocal to the direction of the pointing error. In its strictest form, the target altitude and the direction are not indicated on this type of display. The display finds its use in surface-to-air weapons firing radars. Also called an I-scan, I-scope, or I-indicator.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved