Denmark is upping the stakes in the battle against sulphur polluters at sea with the adoption of new helicopter-mounted sniffer technology.

The Danish Environmental Protection Agency (EPA) has contracted domestic startup Explicit to monitor compliance from passing ships. The monitoring will start from July 2017 and will be conducted from the air by sampling exhaust plumes from vessels in waters around the Danish coast. The Danish EPA said the objective is to “detect and deter” violations of the 0.10% ECA restriction on sulphur in the bunker fuel.

The new “Mini Sniffer System” is said to be capable of measuring both sulphur and NOX emissions to determine compliance, yet is small enough to be carried on a drone. Initially however, the technology will be deployed on a manned helicopter, but with the prospect of phasing in drones as a supplement in the future.

“Our approach is very different from what has been attempted so far,” explains Explicit chief executive Jon Knudsen. “Firstly, we only use rotary platforms because of their ability to maneuver in the plume. Combined with our smart flight software we can guide the pilot on the real-time sensor feedback to optimize the position for sampling. This is important because plumes aren’t clearly visible. Not even on infrared or in case of high emitting ships, so you need navigational support.”

Knudesn, who is a software developer and chemical engineer, says Explicit has also been able to miniaturize the sniffer unit itself to about 500g, making it easy to carry. “Last but not least, we have developed a set of advanced algorithms enabling us to calculate the sulphur content and NOX emissions to reliably determine compliance,” he adds.

The performance and uncertainties of the new system are said to have been validated independently by FORCE Technology, the Danish Government Reference Lab for Air Emissions.

Explicit describes itself as an experienced technology company specialising in affordable systems for sensor data acquisition, monitoring and administration.

In May 2017 Danish authorities fined an unnamed foreign shipowner DKK 375,000 ($57,886) for using high-sulphur fuel within its waters.

The fine was issued by the North Jutland Police on the basis of a notification from the Danish EPA as part of the sulfur surveillance and is one of the first fines – and the largest so far issued in this type of case in Denmark.