Isles become imaging center

A human eye looking down onto the ocean’s surface might see a few shades of blue.

The remarkable optical system developed by a Hawai‘i technology company, Science & Technology International, sees a whale, a turtle or perhaps a submarine.

Already, the same technology, called hyperspectral imaging, is being used to detect nearly invisible changes in skin color that are associated with cancer cells, changes in a tree’s leaves to indicate it is under stress and to pick out the source of a sewage spill in the ocean.

Hawai‘i is a world leader in a range of related imaging fields.

"We have an active community in optical remote sensing," said Bill Friedl, technical director of the Center for Excellence for Research in Ocean Sciences.

The Islands combine skills in astronomy, engineering and other areas and have developed a high-technology niche that gets notice nationwide.

"There is an awful lot of activity going on on the Mainland as well, but I think that Hawai‘i actually holds its own. Hawai‘i is a leader all across the board from astronomy to terrestrial remote sensing," said Jonathan Gradie, president of Terra Systems, one of several local firms in the field.

Many of the Islands’ remote sensing firms, including Terra and STI have built on technology originally developed to identify features of distant stars by their color signatures.

STI, a firm physicist/engineer Nick Susner bought from Hawai‘i astronomers Tom and Carol McCord, is looking at the Earth and into the seas.

During a recent humpback whale count off the north coast of O‘ahu, Susner put his imaging technology aboard a twin-engine Partenavia aircraft and cruised over the same waters being scanned by observers on shore.

"We detected 24 whales, and from shore they detected 23," he said. It satisfied him that the technology is working well.

The military seems to think so, too. Much of STI’s income comes from the U.S. Department of Defense. And much of the detail about the capability of STI’s technology is classified, in part because of its value in detecting submerged submarines and other targets in the ocean.

"I can say that we’ve detected whales at 50 feet and deeper," Susner said.

STI now has 100 employees and is hiring weekly to add to that number. The headquarters is on O‘ahu, with workers also stationed on Maui, Hawai‘i and Kaua‘i, and on the Mainland. Most are on O‘ahu, he said.

Susner’s world is in taking pictures in colors, hundreds of colors.

"Hyperspectral imaging means many colors. We look at things with 288 channels that are looked at with our eyes with only three channels," he said.

When the STI camera looks at the water, if there’s a whale below the surface, its skin sends back a reflection that is a slightly different color from the water around it, although the human eye might not be able to detect it. The shape of the altered color area is compared with shapes already in the system computer.

The imaging system uses algorithms — a step-by-step computerized process that combines the spectral (color) and spatial (shape) information — to identify the patch of discolored water as the image of a humpback whale below the surface. And since the color changes as the whale moves deeper or shallower, the color can be used to gauge the animal’s depth. It also can determine its species.

Susner said the technology is improving all the time.

"We’ve proven that we can do this in a pretty good sea state, in 12-, 15-, 18-foot waves," Susner said.

Susner is excited about the future of the field, and while the military applications are what’s paying the bills today, he hopes medical applications and a range of environmental uses will be the future.

Some of the projects the firm has worked on include identifying the spread of invasive Christmasberry plants in Big Island forests and distinguishing between species of Hawai‘i coral. Using a close-up lens and algorithms more attuned to pinks than greens and blues, the firm is developing a cancer-screening technology.

"Nature has certain color fingerprints," Susner said.

[back to top]