APPARATUS AND METHOD FOR MEASURING EXTINCTION COEFFICIENT OF AN ATMOSPHERIC SCATTERING MEDIUM

摘要

An apparatus and method of determining the extinction coefficient of an atmospheric scattering medium utilizing a transceiver having concentric transmitter and receiver fields, wherein backscattered energy from each of a series of transmitted optical pulses is sampled at two discrete intervals (corresponding to discrete ranges) between successively transmitted pulses and integrated as a function of the ratio of the ranges to provide compensation for differential range attenuation losses. The ratio of the integrator outputs is then obtained and the natural logarithm of the ratio calculated to obtain the extinction coefficient from which a determination of atmospheric visibility may be made.