To describe the light detection and ranging (LIDAR) technique and to discuss recent surveys by Environment Canada which have employed a novel scanning LIDAR system, the “RASCAL”, to study air pollution in British Columbia.
The RASCAL LIDAR system is based on a Nd:YAG laser which emits 0.5 J pulses of IR light at 1,064 nm and green light at 532 nm into the atmosphere at a rate of 20 Hz. The beam is steered by two 24‐inch mirrors and the backscattered signal is detected by a system based on high sensitivity avalanche photodiodes and photomultiplier tubes. The unit is mobile and housed in a small van.
Surveys with the mobile LIDAR identified and located sources of airborne particulate pollution at various locations in British Columbia. A series of high‐resolution elevation scans revealed the complex vertical structure of aerosol layers above the town of Golden. An outcome of this survey was the introduction of local laws banning wood‐burning stoves in new homes in the region. Further, Saharan sand was identified in the atmosphere in the region for the first time.
The surveys showed that mobile LIDAR can detect and characterise airborne particulate pollution and contribute to an understanding of its dispersion and motion in the atmosphere. It will also aid in assessing the associated risks to human health.
