View From the Bottom
Engineer's imaging technology brings
Pearl Harbor battleship into focus
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
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."