The Impact of Choice of Roofing Material on Navaids Wave Polarization

Abstract

Buildings around aerodromes can influence, alter or distort navigation aid system (navaids) signals between the aircraft and ground equipment and therefore risking loss of intelligence in the transmissions. Such interference could have devastating effects on flight navigation especially during landing. Studies on various obstacles on microwave signal transmission have been conducted but very little to investigate and compare the effects of these obstacles on navaids wave polarization. This paper thus focuses on the choice of roofing materials and how they impact on navaids wave polarization.    A transmitter, a receiver and a computer to measure signal level transmitted through roofing materials at a frequency of 9.4GHz were used. The study considered effects of decra, iron, steel, aluminum, plastic and clay materials on navaids wave polarization. From the results, roofing materials have no significant effect on wave polarization. This means that roofing materials have little effect on radiation patterns and therefore radiation patterns cannot be altered by the same in the propagation path. Signal strength depends on angle of incidence and wave polarization. Based on these findings, building industry and flight navigation authorities have been challenged to develop a compromise roofing material.

Keywords: Navaids, Roofing Materials, Transmission, Wave Polarization.