5 min read
Unmanned surface vessels are not only used for good. Drone boats can also be a threat, and those are exactly the hard ones to detect: small, low on the water and fast. We explain why detection is difficult and how sensor fusion and autonomous patrol help.
The threat: unmanned surface vessels
An unmanned surface vessel (USV) can reconnoitre, disrupt or attack without anyone on board. To protect ports, cables and naval ships, it matters to see such vessels coming in time, even when they try to hide among ordinary shipping traffic.
Why detection is hard
Drone boats are small and sit low, so they give a weak radar signature. They often sail without an AIS signal and can manoeuvre fast and unpredictably. On the open sea, with waves and a huge surface, one sensor is rarely enough to reliably tell them apart from buoys, waves or fishing boats.
Sensor fusion: radar, camera and AIS together
The answer lies in combining sensors. Radar sees contacts at a distance, optical and infrared cameras recognise the shape by day and night, and AIS/GPS gives the regular traffic picture. Merging those signals into one picture, sensor fusion, reveals a suspicious contact that each sensor alone would miss.
Autonomous patrol as a mobile sensor
Fixed sensors on shore see only part of the area. Autonomous sea drones bring the sensors to the water: they patrol on their own, cover more sea and can shadow a contact. A swarm of affordable drones delivers continuous maritime situational awareness, with an operator overseeing the whole.
The human decides
The system detects and advises; the operator assesses and decides. That is Level 2 autonomy. Dutch USV Technologies builds the autonomy brain with sensor fusion that makes this possible. It works in simulation today; for the first vessels on the water we're looking for pilot partners at coastguards, ports and defence.