Development of an Airborne Visibility Meter

摘要

A light-weight, compact nephelometer for the detection of cloud presence and the estimation of visual range was designed, fabricated, and tested. The device is intended for airborne deployment for use in a tactical weather observation system and in support of precision guided munition missions. The sensor is a fixed angle nephelometer utilizing an infrared diode at 0.88 micrometers and a silicon photovoltaic detector. The sensor was calibrated in an environmental fog chamber over a wide range of fog and haze conditions. The sensor was found to have a very wide dynamic range of sensitivity (over the decades of attenuation coefficient) and, within operational requirements for accuracy, its performance can be described by a universal algorithm. The nephelometer was field tested at AFGL's Weather Test Facility at Otis AFB; high correlations were observed with transmissometers and other forward-scatter meters.