Abstract

AFGL is developing a mobile coherent, pulsed, Doppler CO2 lidar system designed to evaluate techniques for the acquisition and real-time interpretation of atmospheric wind field structure as well as aerosol attenuation and concentrations over long path lengths . The system utilizes a low chirp electron beam injection CO2 TEA laser which is mode locked by hole injection from a Littrow grating tuned low pressure flowing gas cw CO2 laser . An identical low pressure laser is used as the local oscillator . The entire optical assembly is mounted upon a 3.7m × 8.3m optical table, with the exception of the scanner which is mounted over the table on an elevator system . The scanner system is raised through a hatch in the trailer roof and is capable of full hemispherical and fixed point scanning. The return signal is detected in the usual superheterodyne technique by a Hg:Cd:Te detector. The system IF amplifier output will be split to allow simultaneous real time analog display of velocity as a function of range and digital conversion for obtaining power, velocity, and variance characteristics of the signal. A schematic of the system is shown in figure 1 and the system design parameters are given in Table 1. The entire lidar system along with field operations support equipment will be housed in a modified 12m semi trailer.

© 1985 Optical Society of America