A View From the Bottom

By Alexander Wooley

Prof. Bob Dony's images of the USS Arizona are featured in the June issue of National Geographic.

Photo by Martin Schwalbe

This month, on the big screen and on the newsstands, millions of Americans will revisit events that 60 years ago propelled the United States into the Second World War and altered the course of the 20th century.

Pearl Harbor is the title of a feature film starring Ben Affleck and the subject of an extensive feature article in the June issue of National Geographic magazine - an article with an important U of G connection.

For many, the most tragic event of that fateful Sunday morning was the sinking of the USS Arizona, a battleship that had been lying peacefully at its moorings before Japanese planes dove from the sky. By morning's end, the Arizona lay at the bottom of the harbour, with more than 1,000 American sailors permanently entombed within its decks.

A lasting image from Dec. 7, 1941, is of the Arizona settling to the bottom, smoking and ablaze, her superstructure mangled, twisted and listing unsteadily forward.

Now, millions of readers in the United States and worldwide can see the Arizona again for the first time in 60 years, thanks to imaging technology developed by Prof. Bob Dony, Engineering.

The National Geographic article includes a two-page spread with a clear detailed picture of the entire forward section of the Arizona. "No one has ever before seen the battleship this way," says Dony.

The main reason no one has seen the wreck like this is because, although the ship sits at a relatively shallow depth, the water is so clouded that visibility is just a few feet. Getting an image of the wreck in either small or large scale was impossible until Dony developed technology to make it possible.

In a sense, he began working on the Arizona nine years ago. In 1992, National Geographic explorer Dan Nelson approached Imaging Research Inc. in St. Catharines with a problem. Nelson was referred to Dony, who had worked at Imaging Research at one time.

Dony confesses that when the two first met, he had never heard of Nelson, but soon learned that he had written a feature for National Geographic about two War of 1812 warships he had discovered at the bottom of Lake Ontario, the Hamilton and the Scourge.

Nelson's conundrum was this: instead of the grainy, hard-to-make-out shipwreck images most of us are familiar with, was it possible to take photos of ships in their entirety lying at the bottom of the sea, regardless of the visibility?

That's the question Nelson posed to Dony, an expert on video imaging and signal processing. Dony eventually developed a computer-based program that processes thousands of separate images to produce a single high-resolution composite photo. The digital-video-software process that produces a measurably accurate picture is called photogrammetry.

"The beauty of the system we developed," he says, "is that once you've put together the images, you can zoom into a closeup of one particular spot on a wreck, down to one-sixteenth of an inch in scale, or pull back to show the entire ship rendered in perfect detail."

With Nelson as his connection, Dony got the call last September to go to Hawaii. When he arrived, he realized the challenge that faced him. Brisk tides, silt, algae, plankton and oil still leaking from the December 1941 attack meant that visibility around the wreck was less than 10 feet. Exactly what the Dony and Nelson technique was designed for.

Over the next several days, Dony had divers from the National Park Service swim slowly in careful rows over the wreck at a distance of six feet, filming the ship with digital video cameras. He then took the images gathered and "knit" them together on his laptop.

Although the hours were long, he confesses that the location served as compensation: his usual workplace was a balcony at the Ilikai Hotel near Waikiki Beach. "Under those circumstances, I didn't mind the fact that on most nights, we worked until past midnight."