Detecting turbulence in atmos. from wind speed in selected zone - using Doppler effect between laser beam of predetermined frequency transmitted in measuring direction and returned light

摘要

A laser (L) generates a continuous light beam (EB) which is split into two partial beams (TB1,TB2). The first (TB1) is amplified (V) and split into separate pulses of predetermined length and spacing. These pulses are transmitted in a measuring direction (Ri) in a selected spatial zone (MV). The light (RB) dispersed back from the assigned zone (MV) is modulated by the second unaltered partial beam (TB2). The Doppler shift is ascertained within time periods having a predetermined spacing in time from the transmission time point of the separate pulses and possessing a set time length. USE/ADVANTAGE - Can detect wind speeds at a distance greater than 2Km with a location resolution smaller than 1 Km. Can be installed in aircraft not only to detect increased turbulence and drop in wind by take-off and landing but also during flight for increased safety.