“Breaking ice: it’s a community effort where a large amount of ice is leveled by the use of only hand tools,” said Eyal Saiet. Trail building off Barrow’s shore happens every spring. “It can be more than a month’s effort of breaking trail, so anything that can help breaking trail is of value.”
“Sea ice is changing so rapidly,” said Dyre Dammann. “How is this directly affecting the people that rely on the ice for subsistence hunting, cultural activities and in many ways for their survival?”
Frontier Scientists video ‘Mapping Ice Trails By UAV’ explores new efforts to apply technological advances– agile and programmable Unmanned Aerial Vehicles and ‘structure for motion’ 3-D crafting software– to map sea ice topography in a way that can benefit local communities. Sea ice offshore from Barrow, Alaska, is difficult terrain and the view from a UAV could provide a useful planning tool. Hear about early successes in mapping sea ice terrain from Eyal Saiet, remote sensing specialist, Alaska Center for Integration (ACUASI), a branch of the Geophysical Institute at University Alaska Fairbanks, and Dyre ‘Oliver’ Dammann, University Alaska Fairbanks graduate student with the University’s Sea Ice Group.
Maps for safety
“We have communicated with the population in Barrow over a number of years, trying to direct our research in areas that they are interested in, trying to come up with products that can provide helpful information in a time of rapidly changing ice conditions,” said Dammann. “A very important part when doing arctic research in general and in doing research in areas where there are local people is to all the time keep an open dialog and to conduct research that is important for the community… to provide a product that is of use.” Dammann brought a proposal to use UAVs for sea ice mapping to Native whaling captains of the Barrow community on behalf of the Sea Ice Group currently directed by Andy Mahoney. Dammann explained “We developed this plan and this test flight based on their indication that they would like to see a product that could show where the rough and the more untrafficable areas of the sea ice are.” Techniques for assessing and monitoring ice conditions are valuable, and “Ice roughness has changed in many locations in the Arctic and it’s difficult for the population to assess from the shore.”
“If you want to travel on ice, it can be beneficial to have a map of the ice,” according to Saiet. “A map of ice roughness could potentially be valuable both if you are breaking trail, or if you are just trying to get from point A to point B with the least amount of effort.” When it comes to the arctic environment Saiet says there is a lot to still understand. “There is so much interest in the Arctic because there are people depending on that environment,” and “It’s an incredibly complex topic because that environment is changing.” The joint effort between the Sea Ice Group and ACUASI hopes to “Better support the trail building as it becomes harder and harder to predict the seasons’ ice conditions.”
Dammann stated “Trail building and whaling activity definitely have a risk component.” Dammann: “It’s becoming, in many areas of the Arctic, increasingly harder for many populations to use their traditional knowledge and understand what the quality of the ice is and how safe it is. This is also a time when scientific tools such as remote sensing have recently advanced drastically so we potentially have the ability to fill the knowledge gaps created from the changing sea ice conditions.” Dammann added “Our group has done research in Barrow for over a decade and it is apparent to us from our measurements as well as gathered information from the local population that the ice is becoming more and more unstable associated with potential safety concerns.
”In both 2013, and 14, the ice broke out with hunters on it. And one of the years the crew members drifted off for several miles under extreme weather conditions.”
“This really emphasizes the importance of these products which we hope will provide additional guidance to local expertise about the ice to be able to choose a preferable trail location that is safe as well as trafficable in terms of labor and cost.”
Ridges for safety
What properties of the ice are Native communities dependent on, and how are these properties changing? “If you stand and look out over a piece of ice is it safe to go on? It’s a more complex question than you might think,” Dammann said. “How does that impact the people who are dependent on that ice? This could be industry, traveling on an ice road or building an ice road from the North Slope of Alaska and it can be local communities that want to connect their two communities with an ice trail.”
Local knowledge and geophysics look at ice stability, thickness, and roughness, and how those properties change in the span of weeks to years. Saiet described how Sea Ice Group scientist are “Exploring these new ways of making data sets and how they can improve our understanding of systems how they can support management of emergencies.” With a view obtained flying, maps reveal important sea ice characteristics. Dammann noted “By assessing the topography of the ice by using a UAV you might be able to sort out where are the smoothest paths,” and “In general smooth ice is beneficial for trail builders– makes is drastically easier for them to get from shore and out to the ice edge which is the ultimate goal.”
“That’s not the whole story though,” Dammann added. “There are certain features called grounded ridges: piles of ice that are so large that they ground themselves to the sea shore creating additional stability.” When trails are plotted near grounded ridges “It makes it safer for the crew since the ice is less likely to break out in a wind or current event.”
Saial described “There is landfast ice and then there is the ocean sea ice. Landfast ice is pretty much static for long periods of time because it is fastened to the sea bed.” Landfast ice is thick and characterized by pressure ridges that can prove big obstacles to trail building crews. Thinner ice, not thick enough to reach the sea floor, is more temperamental and changeable. Dammann said “Often they set up what’s called a safe camp close to or behind a grounded ridge. So if the wind picks up quite a bit and they are concerned that some of the ice might break out, they will haul their equipment back behind this grounded ridge to wait.” Spotting grounded ridges from the air can help pick out safe spots and efficient routes to trailblaze. “This is thousands of dollars of equipment. It’s pretty crucial that they protect those assets.”
During breakout events, winds and currents can make sea ice break apart and float away from shore. “If we have a topographic model of the ice we can use this to understand how wind forces ice and how ice will move. So in the end those whalers that were stranded on the ice, basically they had a big wind gust that came and pushed that ice away. So if we knew more about the topography of the ice, we can predict better when ice will break off,” Saiet said. Rough sea ice is more susceptible to being pushed by wind, and maps can show that roughness or smoothness in astounding detail.
Test maps showed polar bear footprints on the snow. Saiet: “It’s very very detailed– particularly if you fly low– each pixel, each feature will map as a centimeter.
“If you have a polar bear footprint that is bigger than the palm of my hand, you definitely can see the feature, and it’s detailed enough and in depth enough that you can actually measure the indentation of the palm on the snow.”
UAV technology
ACUASI engineers added an open source auto pilot to a small hexcopter UAV dubbed a Ptarmigan. Saiet said “It can take about 2 lbs, 2.5 lbs for 20 minutes. And it was great for us to try this technology for remote sensing, making maps on a small scale.” The Ptarmigan was set up to follow a pre-programmed grid once it was in the air, using auto pilot to navigate over points of interest the team had selected and inputted. The scientists entered waypoints on a laptop and instructed what kind of overlapping images to take, and created a grid for the Ptarmigan to follow. A DSL camera mounted on the Ptarmigan took myriad overlapping images during the flight– capturing images every second or every fraction of a second. Later, the images were processed by software which applies a technique called structure for motion. Saiet: “It will find common features from each image and stitch them together for a 3-D model.” Each image is also tied to a GPS location, resulting in a highly detailed 3-D map tied to physical locations. The map can be printed or viewed on mobile devices. The images were so detailed that it took significant processing power and a few hours to process the data set. “The day after we made the map, we met with them again on the ice with those trails and we printed those maps,” Saiet said. For this test-run “Of course we mapped a very small area. For the future we need to make something significantly bigger.
”Both the scientists and the locals were very very interested, and we as an organization learned a lot about how to conduct these things in this kind of environment. And we hope to expand what we are covering next year.”
Zero degree temperatures and wind chill over the course of 10 hours of testflight outside of Barrow did pose some challenges. When it comes to technology cold is rough on batteries and battery-changing fingers alike. The Ptarmigan runs on lithium polymer batteries, the same ones that Tesla vehicles run on. Saiet: “Due to safety, we have the pilot have his hands on the remote control, it has joy sticks… If I need to program the instrument that is on the aircraft I use my laptop and I have to use my own fingers on my laptop; all these little things, they offer opportunities for hands to get cold.”
The scientists’ experience
Dammann said he wasn’t sure of how the test flight would go over. “We had communicated and received permission from the whaling captains, but that was only a handful of people who knew we were going to do this.” Dammann estimated 4 or 5 whaling crews were working the trail and there were 30 to 40 people around including kids. “Everyone comes out there and has a good time breaking trail,” he observed. “They are using basic hand tools, just like the old days, often in their traditional outfits and they are chopping trails through this very rugged ice which is very hard labor.
”It feels like stepping back in time to go out there and witnessing this tradition.”
“You are standing there as a scientist and you are flying this highly technological UAV in their direction and, yeah, we weren’t sure how this was going to be taken at all. But as it’s coming towards the population or the trail breakers, you are seeing a whole bunch of people pulling up their iPhones and taking pictures of the UAV.” Dammann recalled “They were all very interested.”
“We were able to perform a trail survey using this UAV over or close to active trail building without interfering in any of their activities. And they were happy with our presence there and didn’t think that it was an inconvenience to them. That was a huge success for us, to be able to do that,” Dammann said, “And providing a product that they had great interest in.”
Saiet: “There’s definitely a lot of future in combining UAVs and sea ice and arctic research. That’s for sure.”
Laura Nielsen 2016
Frontier Scientists: presenting scientific discovery in the Arctic and beyond
(UAVs trail building potential sea ice maps)
