Abstract

The Titan Spectron Airborne Laser Transit Anemometer¹,²,³ based on measurements of particle transit time between pairs of sheets, was designed to determine the relative velocity vector between an airborne vehicle and its surrounding medium. Measurements in the upper atmosphere from a NASA F-104 aircraft suggest that the instrument can also estimate the size distribution and concentration of atmospheric aerosol particles. The energy detected during transits of the sensing sheets by individual particles, together with current values of monitors originally intended for diagnostics and performance logging permits an estimate of the radius of each particle under well defined assumptions which are discussed below. Signals from up to 900 particles per second can be individually reported to the aircraft 1553 bus, with properly sampled statistics where there are more than 900 /s. A distribution of particle radius and an estimate of concentration may be derived from these data.

© 1992 Optical Society of America