How laser scanning may help crack mysteries of HMS Erebus

When Sir John Franklin set sail from England in his 1845 bid to find the Northwest Passage, the reinforced British warships in his expedition were renowned for the scientific and naval innovations on board.

But none of that technology was enough to save HMS Erebus and HMS Terror from the ravages of thick Arctic ice and all the other forces that conspired to doom the polar expedition and its 129 men.

Now, however, cutting-edge Canadian underwater laser technology is giving Parks Canada a high-tech hand in its efforts to unlock the mysteries hidden within the wreck of the recently discovered HMS Erebus.

Data gathered by a long-range underwater laser scanner developed by 2G Robotics Inc. of Waterloo, Ont., is helping Parks Canada's underwater archeologists create the detailed 3D scan they want for planning future forays to the Franklin Expedition shipwreck in Nunavut.

"Whenever you're dealing with archeology, it's often the newest technologies that shed the most light on some of the history of the oldest and most uncertain expeditions," said Jason Gillham, founder and CEO of 2G Robotics.

There's still a lot of uncertainty surrounding the Franklin Expedition, even though searchers discovered HMS Erebus lying remarkably intact 11 metres below the surface of Queen Maud Gulf late last summer.

The latest effort to unlock some of the uncertainty wrapped up on April 18, when Parks Canada underwater archeologists and Royal Canadian Navy divers completed six days of diving through the two-metre Arctic ice.

Because the thick layer of ice eliminates wave action, letting all the particulate settle at the bottom, archeologists considered the conditions prime for deploying the long-range laser scanner Parks Canada bought from 2G Robotics.

"We want to take advantage of the water clarity to do a very thorough baseline recording of the wreck site before any future interventions take place," Ryan Harris, a senior underwater archeologist for Parks Canada, said in an interview earlier this month.

"We'll start externally and slowly work towards internal documentation. That is indeed where things are probably going to get quite interesting in the years to come, where we stand to learn, hopefully, what happened."

Very impressed

But first, they need the detailed data the long-range scanner can help provide.

Parks Canada has been "very, very impressed in terms of the amount of data it can collect and the overall accuracy and precision of the data," Harris said.

2G Robotics developed the long-range underwater laser scanner with guidance from Parks Canada, which was looking for such technology after the 2010 discovery of the wreck of HMS Investigator, a British merchant ship that had been sent to find Erebus and Terror.

"It's on a stand and it pans around," Harris said of the scanner, noting it sends out a vertical slit of blue-green laser light and registers a three-dimensional image of what it can see.

Gillham says the core component of the technology are the calibration techniques used to help a diver position the scanner precisely on the sea floor, clearing the way for accurate measurements of the target — in this case, Erebus.

Power and ethernet cables connect the scanner to the surface, where an operator in communication with the diver controls the scanner, sweeping the laser over the target. Data gathered in a point cloud will appear live on the operator's screen.

As the data comes in, it will render the 3D model.

"There's all sorts of different ways of interacting with it," said Gillham, noting the potential of "everything from creating 3D printings from the data that's been collected through to virtual reality-type interactions to just straight photographs or pictures."

Not like ordinary pictures

Those photos aren't quite like anything a regular camera would produce.

The data comes back with what Gillham calls an "intensity return" that gives "some level of colourization" to every point recorded.

"You can then colourize that in a whole bunch of different ways … but one of the common ways is just to use grey-scale imagery."

2G Robotics also loaned Parks Canada a smaller, medium-range underwater scanner that would be able to manoeuvre inside nooks and crannies of Erebus.

"It would just give [the underwater archeologists] some more flexibility while they were there," said Gillham.

Work such as Parks Canada's underwater exploration doesn't fall within 2G Robotics' main market, which is energy-based industries such as offshore oil and gas.

But it does venture into a field that has been a lifelong interest for Gillham.

"We're always interested in getting involved in the scientific and exploratory-type applications because of the intrigue that they have and the stories around them."

Other projects

The company's technology was also deployed after the Costa Concordia sank off the Italian coast in 2012, helping determine where to attach floats to the downed cruise ship.

Gillham says he wouldn't be surprised if some of the company's customers, who have some of its gear, might be called upon if the missing Malaysian Airlines MH370 jet is found in the Indian Ocean.

But closer to home, Gillham relishes the chance for his firm's technology to be part of the Franklin Expedition exploration.

To be able, he said, "to contribute to such an iconic Canadian history story with very new technology is really pretty fascinating for me."