How many photos do you figure you shoot out the window when you take a trip? 5? 10? 20? How many of you take a picture every three seconds?
KUCB’s Zoe Sobel caught up with a helicopter crew of modern mapmakers who shoot 3-5,000 photos a day.
Imagine looking out a helicopter window taking pictures as you’re traveling 60 miles an hour and you’re only 300 feet over the Eastern Aleutian Islands.
That’s a typical day for the four-person ShoreZone flight crew. But why spend so much time when there are satellites?
“People have said well why don’t you just use satellite imagery so you can get one picture of everything. But of course the satellite picture is also limited in resolution,” said oceanographer Carl Schoch. “If we’re trying to resolve objects on shore that are on the scale of centimeters. That’s actually very hard to do unless you get this kind of imagery.”
Schoch added that there actually are no maps like this.
“There are lots of other coastal maps out there — navigation charts, topographic maps — there are even other maps of shoreline habitats but none that match the imagery up with the map,” Schoch said.
The team can map the shoreline biology because the photographs are shot at an angle, which makes it easier to see cliffs and overhanging vegetation.
Over a week, they are documenting more than 1,300 miles of shoreline through video and still imagery. But there is a short window each year for photographing the shore – it can only be done during extreme low tides in the spring and summer when the intertidal flora is blooming.
To get everything done, the team is on a tight schedule with every five minutes mapped out. Any delay can ruin the entire day.
“All it takes is one flat tire or if anything were to happen here and all of a sudden the whole day is shot. We couldn’t go out,” said Schoch. “That one event would just destroy the whole project. We don’t have an extra day at the end of the tide to make it up. Coming back for 400 km of shoreline isn’t worth it.”
Back in the lab in Victoria, British Columbia, the thousands of still images are stitched together using a technique called structure form motion. Every single pixel gets a latitude, longitude and elevation creating a 3-dimensional model of the shoreline. And that step takes a long time. It will be at least six months before this project is completed.
Online everyone can access ShoreZone’s maps and video. When the program began in the 1980s, it was intended for oil spill responses. But over the years, that has changed. Schoch said people can use the data in many ways.
“From beach walkers to people who are planning for making development plans on the coast or very large ecological questions that have to do with the entire gulf of Alaska, this project has relevance to all of them,” Schoch said.
In the winter months, Archaeologist Martin Stanford scrolls through the still photographs and video. The photos help him plan summer trips to explore old village sites where he can document stonefish traps and canoe ramps built nearly 600 years ago.
This trip to the Eastern Aleutians is part of a larger project mapping the entire coast of the Pacific Northwest. Alaska is 90 percent done while the coasts of Washington, Oregon and British Columbia are completed.
Certain areas of Alaska’s coast have been mapped more than once. With the ShoreZone project nearly finished, Schoch thinks people will be interested in seeing how fast their shoreline is changing.
“Now that we are thinking about remapping this becomes relevant because we can compare old 3D models to new 3D models and we can measure the change on a shoreline due to wave erosion or sea level rise,” said Schoch.
Zoe Sobel is a reporter with Alaska's Energy Desk based in Unalaska. As a high schooler in Portland, Maine, Zoë Sobel got her first taste of public radio at NPR’s easternmost station. From there, she moved to Boston where she studied at Wellesley College and worked at WBUR, covering sports for Only A Game and the trial of convicted Boston Marathon bomber Dzhokhar Tsarnaev.
