Abstract

An airborne DIAL system with two-color CO₂ lasers has been developed for remote sensing of 3-D ozone distribution in the lower troposphere. It is an active nadir-directed system, designed to use tropospheric aerosols as the distributed radar target. A twin-engine Aero-Commander was selected to carry the system. The transmitter of the DIAL is composed of two mini TEA CO₂ lasers and a telescope. Typical output energy of the laser with a SiC ceramic preionizer is 200 mJ. The receiving telescope has an almost diffraction-limited primary mirror with a diameter of 300 mm and an f/No. of 2 to collect photons efficiently. The signal is detected with a 1-X 1-mm HgCdTe detector by means of direct detection. For the first step of our DIAL system development we built an airborne one-color CO₂ lidar and made flight tests of the lidar to detect tropospheric aerosol backscattering at 10.6-μm wavelength. Flight tests were successfully conducted in February 1985 over the Tokyo area at an altitude of 5000 ft(1.7 km). Results of the flight test showed that height profiles of receiving power corrected by a range-squared over ocean were more variable than those over land. We discuss more details of the flight test.

© 1985 Optical Society of America