Influence of Aircraft Body on the Signals from ILS Localizer

Abstract

The disturbance of ILS localizer signals by reflections from taxing aircraft is described in this report. The results measured in two different configurations are presented to study the disturbance. First, measurements were made to obtain the fundamental characteristics of ILS localizer, such as radiation pattern, clearance and course structure in case that there is no aircraft. Second, the degradation of the localizer performance was measured by locating aircraft on the taxiway behind the localizer antenna. These measurements were made both on an airport ground and by air. It has been shown that the influence of aircraft body was conspicuous in clearance and the course deviation was about 4 micro amperes in this configuration.