The OLEX aerosol-ozone lidar system on the Falcon. The instrument consists of two lasers, one emitting at 1064 and 532 nm (Nd:YAG) and the other at 308 nm (XeCl-excimer). Backscattered light is collected through a telescope mounted at the bottom of a hole cut into the rofo of the aircraft. Data from this instrument provides detailed information on the structure of polar stratospheric clouds as well as the distribution of ozone (and rates of ozone depletion) in the Arctic stratosphere. Space is rather limited inside the Falcon. Typically, three scientists accompany the pilot.