Volumetric scanning GCA antenna

Ground oontrolled approach (GCA) landing of aircraft under conditions of poor visibillity is a rather natural application for microwave radar. This fact has been aptly demonstrated by the AN/CPN-4 system and its improved successor, the AN/FP-l6. These GCA radars, which operate at X-band, obtain elevation and azimuth information by sweeping two adjustable fan beams across the airplane being controlled. The sets operate quite successfully in landing a single aircratt and can handle two or three at a time on a staggered approach. However, there are a number of improvements needed in GCA radars, among which are the following: the ability to handle the increased air traffic at large commercial and military airfields; an increased range on small jet aircratt under adverse weather conditions; reduction of ground clutter; and increased resolution. In an attempt to obtain these and other improvements, the Rome Air Development Center has sponsored the development of a volumetric scanning GCA antenna through a cross-servicing arrangement with the US Naval Research Laboratory. The new X-band antenna, utilizing four pencil beams will rapidly scan the 7°x 20° sector solidly at rates up to tour frames per second.