Students take to the air to create three-dimensional maps of River Falls park

Posted December 7, 2015

Two UW-River Falls students have been taking aerial photographs with a balloon and a GoPro camera this semester to create three-dimensional maps of Hoffman Park.

International student Diego Valadares and UWRF senior Jason Blatz said that they wanted to do something different for their final project in Field Methods and GPS (Geography 366). Instead of using a GPS system to help them map different features from the ground on and around campus, they decided to look at River Falls from above.

To take the photos, they launch a helium balloon with a GoPro attached to it set to take a photo every two seconds. Any camera could be used, but Valadares said that they chose a GoPro because of its size and image quality. A picavet system made of string, pulleys and wood keeps the camera stable and facing the ground. The string passes through the pulleys as the balloon moves, and the wooden cross with the camera attached to it settles into a level position.

However, the system isn’t perfect. Valadares said that post-processing of the photos has to take place before the final product can be created.

“We pass all of the images through Photoshop to correct the lens distortion,” Valadares said. “And after that, we get those images together and put them into another software to generate a 3-D model of the area.”

The photos are placed into a program called Agisoft PhotoScan, software that places the images and overlaps them to create 3-D maps. Blatz said that the program can determine the height and angle of the photos correctly, but entering GPS coordinates can give a more accurate result.

“It’s kind of like a mosaic, and then with that, it’s building a 3-D model,” Blatz said.

Their instructor, Associate Professor of Geography Matt Dooley, said that this type of work is particularly important because aerial images aren’t always updated regularly.

“We don’t have really great aerial imagery when we need it a lot of the time,” Dooley said. “So a really good example of that would be an emergency disaster situation.”

Dooley said that while Google has its own maps, they aren’t updated enough to give relevant information about current situations. According to the Google Maps help forum, most of the images are between one and three years old.

“It’s really exciting because we can get more detail, hopefully, and get the photos when we want them,” Dooley said.

Dooley said that Valadares and Blatz’s project is another way to show that geographers do more than sit at computers all day.

“While that’s a really important thing, especially in cartography, that’s not all that we do,” Dooley said. “So I think it’s important to highlight that we actually go out into the field and do things as opposed to just sitting in cubicles.”

On Dec. 3, Blatz and Valadares launched the balloon on campus for the first time and captured photographs. They presented some of the images along with their research from the semester at the Undergraduate Research, Scholarly and Creative Activity’s Fall Gala that evening.

This is the final semester at UWRF for both Blatz and Valadares, with Blatz graduating and Valadares returning to Brazil. Blatz said that he’d like to use this semester’s work to do more research with his own resources. He said that if he decides to attend graduate school, he will likely base his work on this project. Valadares said that he also intends to continue taking aerial photographs to map parts of Brazil.