Design and Evaluation of Visibility Sensor/Runway Visual Range Computer Interface Circuitry.

摘要

Runway visual range (RVR) is an aviation visibility value obtained by utilizing a special purpose signal data converter. Atmospheric transmittance, one of the processing parameters used, is provided by a National Bureau of Standards type transmissometer that samples clarity of the atmosphere by measuring the amount of incandescent light from a known source remaining in the beam after passing through a baseline distance of 500 or 250 feet. New types of visibility sensors are now being produced that operate on a light-scattering principle rather than attenuation. These new types of sensors are being considered as alternatives to the NBS transmissometer. If found suitable, these new sensors will require signal conditioning circuitry in order to operate in conjunction with existing, standard-type RVR computers. This report describes the design and testing of such an interface circuit to permit use of the EG and G model 207 Forward Scatter Meter (FSM) with the RVR computer. It was concluded that the circuit design does provide accurate interface between the EG and G model 207 FSM and FA-7871-type signal data converters.