Laser-based sensing technology is finding applications in maritime remote inspections, dynamic positioning and now ship navigation
Light detection and ranging (Lidar) uses lasers to position objects in a 4D space with three dimensions for movement vectors and the fourth for time. This is ideal for navigation when satellite positioning is unavailable.
Lidar can be used to augment radar during ship navigation. This is what Ladar Ltd (laser detection and ranging) has achieved for various maritime sectors. It is testing this technology for long range detection of navigation hazards.
It is conducting trials on ferry Color Magic as it sails between Oslo, Norway, and Kiel, in Germany. It is also being used for fish inventory assessment and bathymetric/sea floor mapping by aircraft and floating mine detection for a navy.
Ladar has letters of intent with Team Tankers Management, Hurtigbåtforbundet HRF, The Fjords, GOTA Ship Management, Hargun Havfiske, Barents Nord, the Port of Rotterdam and Grand Large Yachting.
A laser pulse scans a specific area or tracks specific targets with over 100 readings per second. It can detect objects in the surface layer up to almost 2 km and to a depth of 10 m. It can detect floating objects, a person, small craft, icebergs, marine mammals and environmental factors such as waves or pollution.
“The system’s proven capability to detect, characterise, classify and track various surface-layer objects in real-time makes it suitable for a wide variety of applications,” says Ladar principal Sverre Dokken.
“It overlaps many existing ship radar functions with added benefits, high-speed operation and no latency,” he adds. This device can be configured to different light bandwidths as required.
Ladar can incorporate laser diodes together with an optical camera, gyros, optional AIS, and radar and sonar feeds to produce a comprehensive analysis of the ocean surface layer ahead of a vessel.
Its data is accessed on a graphical user interface or through a virtual and augmented reality device. Data can be analysed through AI to continuously improve detection and classification capabilities. It can be used to reroute around navigational hazards, to chart marine plastic pollution, wave spectrum and ocean current observations, and to map moving sandbanks and uncharted reefs.
Lidar is already used commercially for dynamic positioning with laser-based positioning systems. It is now being used for navigating survey drones where GPS signals cannot be guaranteed and will be used for navigation in the future.
DNV GL and Scout Drone Inspection completed the industry-first inspection of an oil tank on a floating production, storage and offloading (FPSO) vessel in Norway in June, using a drone with a Lidar device in the enclosed space.
Lidar created a 3D map of the tank and enabled all images and video to be accurately geo-tagged with position data. During the tank inspection, a pilot remotely controlled the drone using Lidar and flight assistance functions.
The drone inspected a 19.4-m high oil tank on Altera Infrastructure’s FPSO Petrojarl Varg. Video from the drone inspection was live-streamed to DNV GL’s surveyors and, via Scout Drone Inspection’s cloud-system, back to Altera Infrastructure’s headquarters in Trondheim, Norway.
DNV GL developed artificial intelligence (AI) to interpret the video to spot any cracks. The camera and algorithms will detect anomalies below the surface such as corrosion and structural deformations.
Altera Infrastructure production department’s senior vice president for technical and projects Astrid Jørgenvåg expects more surveys to be completed with drones using Lidar technology. “We see great potential for drone inspection technology to meet the challenges of the inspection process going forward,” she says.
There is a future for Lidar-positioned drones for more types of class survey, says DNV GL Maritime director of offshore classification Geir Fuglerud.
“This latest test showcases the next step in automation and using AI to analyse live video,” he says. DNV GL will use technology advances to make surveys more efficient and safer for surveyors, “delivering the same quality while minimising operational downtime for our customers,” says Mr Fuglerud.