Optical design of precision approach path indicators in a portable runway lighting system

Abstract

Portable runway lighting systems pose an interesting illumination challenge. They are typically used in harsh environments where generators or batteries are used to provide electricity. As a result, not only do the systems have to satisfy the regulatory requirements which determine the light intensity profile but they also need to be highly efficient and within a compact design. This paper summarises the optical design and performance of a PAPI system using LEDs which are coupled into a waveguide to generate the required light distribution at an intermediate plane after the waveguide. The use of waveguides means that a single projection lens is used to generate the final beam and this images the output of the waveguides into the far field.