Improved Antenna Systems for ILS Localizers

For many years Norwegian airports have been equipped with instrument landing system (ILS) localizers of conventional type. Most of the localizers, however, were found not to perform very well on these sites. The course bends were too large and even moderate amounts of snow and ice could cause the localizer to fall out of operation. To overcome these difficulties, the requirements for localizer operation at these airports were analyzed and a new and improved antenna system developed. After a long period of operational testing, during which it was made clear that a substantial improvement in performance had been achieved, the new localizer antenna system is now in operation at 13 Norwegian airports.