Research Spotlight: LiDAR for Air Quality Measurement

A research team of scientists from Old Dominion University (ODU) and Virginia Tech (VT) is taking the term ‘adaptability’ to new heights. Having access to a state-of-the-art LiDAR system from the NASA Langley Research Center, the scientists are taking an innovative approach to repurposing the technology to address air quality and pollution levels in relation to traffic patterns in the Hampton Roads area.

Light Detection and Ranging (LiDAR) is a remote sensing technology that measures distance using a pulsed laser and reflected light. The NASA LiDAR system has been used for many years to measure aerosols in the atmosphere from flying aircraft. However, Khan Iftekharuddin, Ph.D., and Mecit Cetin, Ph.D., from ODU, and Hesham Rakha, Ph.D., from VT, saw an opportunity to use the LiDAR system in a new way. By adapting the technology to measure different types of ratios (Lidar, depolarization and color), they hypothesized that they could obtain continuous measurements of particulate matter (PM) in the atmosphere over a large area of increased vehicular traffic. The PM in the atmosphere, one of the factors for air pollution caused by vehicle emission, would be measured in a way that is not currently available. The major pollutants of vehicles emissions in the atmosphere include hydrocarbons, carbon monoxide, nitrogen oxides, sulfur oxide, and organic compounds. (i.e. soot and organics).

Why is this important? Iftekharuddin explains that, “current methodologies for measuring PM specifically from ‘hot-spot’ traffic congestion (such as at tunnel entrances or in high truck traffic areas) often involve hand-held localized vehicle emission measurement technologies. These devices take vehicle-by-vehicle measurements. This approach is not very efficient nor does it provide aerial measurements in a broad area. So it’s often difficult to draw conclusions about health and environmental risks in relation to specific traffic conditions and flow patterns.”

The MATS UTC research grant brought the three researchers together around shared interests in intelligent transportation systems and their expertise to analyze and classify LiDAR measurement data related to engine exhaust during various traffic conditions. Initially, the project is focusing on analyzing the variation in PM distribution over time and space, in relation to the variation in traffic levels. The researchers hope to validate this new approach as a way to correlate traffic flow and congestion with estimated vehicle emissions. Ultimately, they hope that this technology will provide local governments, departments of transportation, and public health and policy organizations with better information upon which to make traffic management and land usage decisions.

Mecit Cetin is an associate professor of civil and environmental engineering and is the director of the Transportation Safety Institute at ODU. Dr. Cetin conducts research in various areas including mining big transportation data, modeling and simulation of traffic operations, congestion pricing, freight transportation, sustainable transportation, traffic signal control, probe vehicle technologies, and system state estimation in transportation networks. He earned his Ph.D. in Transportation Engineering from Rensselaer Polytechnic Institute. He may be contacted at

Khan Iftekharuddin is professor and chair in the department of electrical and computer engineering at ODU. His research has focused on signal and image processing, computer vision, neural networks applications, time-frequency analysis, sensors and embedded system design. He received his Ph.D. in electrical engineering from the University of Dayton. He may be reached at

Hesham Rakha is a professor of civil and environmental engineering in the College of Engineering and director of the Center for Sustainable Mobility at the Virginia Tech Transportation Institute. His research focuses on creating traffic models that improve transportation system efficiency, improve transportation safety and reduce automotive emissions. He received a Ph.D. in Civil Engineering from Queen’s University in Kingston, Ontario. Dr. Rakha may be contacted at