Abstract

We describe in this paper results of a system study for an airborne lidar system that makes real-time, range-resolved measurements of clear air turbulence (CAT) to several kilometers forward of an aircraft's projected flight path. Exploiting the width of the IF signal Doppler spectrum (σ_f) is central to the system concept. Since broadening of the Doppler spectrum beyond the transform limit is a function of the mixture of velocities (velocity width, σ_v) in the pulse scattering volume, any combination of shear and/or turbulence in the flight path is immediately revealed by the broadened spectra. Hence, σ_f relates to a property of the velocity field that is particularly important to aircraft anti other aerospace vehicles. Explicit spectral width processing is quite powerful for CAT detection lidars because complex atmospheric wind patterns can be characterized in terms of a single observable σ_v for subsequent reckoning against a hazard index.

© 1993 Optical Society of America