A New Lidar for Meteorological Application

Abstract

A new lidar has been demonstrated to be potentially useful as a meteorological tool. This lidar is the result of applying a new technology, gallium-arsenide fiber coupling. By coupling optical fibers to each of an array of gallium-arsenide diode lasers, a narrow, well-collimated, relatively high flux density laser beam is attainable from a mall package. This, in conjunction with pulse repetition rates in the kilohertz region, permits the construction of a practical lidar with a good signal-to-noise ratio and peak power within the limits of eye safety. Examples of signals from some hydrometeors (rain, fog and clouds) using a 250 W peak-power lidar are presented. Cloud height measurement to 4000 ft has been attained. The possibility of measuring cloud extinction coefficients using such signals is demonstrated. The potential of measuring extinction coefficient profiles (and thus visibility profiles) through fog is also demonstrated.