Environmental Sciences Western Field StationWestern Science

Purple Crow Lidar

Purple Crow LidarThe PCL is a laser radar (lidar) which operates from the Echo Base Observatory located at Western's Environmental Science Field Station located near London, Ontario, Canada at 43.1° N, -81.34° W, (elevation 275 m above sea level; for directions to Echo Base click here.).

The powerful laser emits pulses of light as bright as simultaneously turning on 1 million 75 W light bulbs! The laser light scatters off air molecules. The reflected light is collected by a large telescope formed by rotating liquid mercury at 10 r.p.m. in a 2.65 m diameter container. The liquid mirror technology has been made practical by innovative work Purple Crow Lidarperformed at Université Laval in Québec City. The measurements allow air density, pressure, temperature and composition (for instance, water vapour) to be measured. These measurements will be used to address the question of global warming in addition to contributing to our ability to predict weather.

The PCL research project is headed by Professor Robert J. Sica of the Physics Department at theUniversity of Western Ontario