Application of Remote Sensing Tunable Laser Technology for MeasuringTransportation Related Air Pollution

This paper presents initial results of the air quality analysis project that is focused on remote sensing laser measurements of air pollutants and air quality impact of transportation systems. Tunable laser remote sensing technology is being used over a distance of several hundred meters for measuring Nitrogen Dioxide and Ozone related to transportation. The laser is tuned between ultraviolet, visible, near infrared, and thermal infrared spectral regions. The difference in the absorption of light at these different wavelengths is used to determine concentration of air pollutants. The absorption band of Nitrogen Dioxide lies in the visible part of the electromagnetic spectrum. It absorbs blue color of sky, resulting in brown color smog. The laser measurement results of Nitrogen Dioxide concentration, measured near Mississippi Highway 6 in Oxford, showed nearly 25 times more concentration at 10 AM (daytime) compared to the measurement at 11 PM (nighttime) when the traffic was minimal. Higher Nitrogen Dioxide concentration is also associated with higher air temperature in the daytime measurement.