A research team of Institute for Environment and Sustainability, led by Prof. NING Zhi and co-supervised by Profs. Jimmy FUNG and Alexis LAU, has been working with the Hong Kong government’s Environmental Protection Department to develop a proof-of concept protocol to measure real-time fuel sulphur content from ship emissions to help the enforcement of the tightened Air Pollution Control (Fuel for Vessels) Regulation that mandates all vessels within Hong Kong waters to use compliant fuels with a sulphur content less than 0.5%. The project employs an advanced unmanned aerial vehicle (UAV)-based system with a highly compact sensor package. The system can fly near to the vessel funnel, within 50 meters, to conduct real-time measurement of carbon dioxide (CO2), nitric oxide (NO), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO) and particulate matter (PM) concentrations. Facilitated by cloud-based real-time data communication and computing, the system is capable to measure the FSC in 2 minutes with an accuracy rate of over 90%. The new senor system is way more effective than the current practice of examining vessels’ fuel-use log-book, visual inspection on smoke opacities, or extracting fuel samples from vessels for analysis.