An Experiment on EL/GP Collocation Antenna System

Abstract

We have studied the effect of MLS EL (Elevation) antenna on ILS GP (Glide Path) structure by flight experiment and computer simulation.

In this study, we installed a mock-up of EL antenna at various points in front of the GP antenna, and measured the GP structures. And also, GP structures for the similar sitings are calculated by means of GTD (Geometrical Theory of Diffraction).

Both results have shown good coincidence, and we have found that the area where collocation of EL and GP antenna shall conform to the ICAO standards for ILS GP structure, is wider than previously suggested by other papers.