SENSOR SYSTEM FOR ASSESSING VISUAL RANGE ON A RUNWAY.

摘要

Pilots operating to or from an airfield require knowledge of visibility in the vicinity. In adverse weather this is supplemented by assessment of runway visual range' (RVR). RVR is often assessed using visibility sensors located adjacent to the runway but, for safety, some distance from the edge. The proposed method employs the principles of forward and/or backward light-scattering geometry using the runway light fittings as light sources, enabling RVR to be assessed actually on the runway. The larger number of sensors also improves knowledge of the spatial and temporal variation in visibility along the length of the runway. The diagram shows part of an array of runway light fittings L1, L2, L3, etc. each producing well-defined beams (towards the right). Light scattered from the beams by aerosols is measured by photo-sensors located on adjacent fittings. The measurements can be used to assess RVR along the length of the runway.