KU News Release

LAWRENCE — Imagine peering out your back window to see a parachute laden with strange silver boxes drift from the clouds and end up snared by a tree in your backyard.

It was a mystifying event for one Johnson County resident, until geography students from the University of Kansas arrived minutes later in a chase vehicle to explain: the parachute and equipment all were part of a class project involving a camera, GPS locator and high-altitude balloon that minutes ago had climbed beyond the Earth’s atmosphere, about 20 miles above Kansas.

It was just another day in the life of Project GeoHawk, an outgrowth of a geography class taught by Kevin Dobbs, lecturer with the geography department and project coordinator with the Kansas Biological Survey.

“Project GeoHawk is an assignment for an advanced remote-sensing class that charges the students with designing, building, launching and recovering a high-altitude balloon-based remote-sensing system,” said Dobbs. “The second phase has them taking the data they get from their flight and using it to do a research project.”

Dobbs conceived of the undertaking because he wanted his students to better know how aerial imagery is produced “with all its warts.” Many of his students during their future careers will analyze photos gleaned from satellites, aircraft and other remote sensing platforms.

“Most of the students are geography students, and we have some geology students,” Dobbs said. “They’re both graduate students and undergraduates. The majority are graduate students. Our focus is on satellite-born sensors, airborne sensors. Often, you receive those data that have already been processed, and I wanted to give the students the chance to get their own data, so they could work through the imperfections and figure out what those imperfections mean. In the workforce later, they’re going to be given things that aren’t perfect.”

The students divided themselves into multiple teams — including a camera team, tracking team, logistics team and public relations team — and set about working together to accomplish two separate balloon launches.

Each helium-filled latex balloon was equipped with a high-end digital Olympus E-5 camera that was loaned to Project GeoHawk by the manufacturer. Also, the balloons carried a GPS device and radio transmitter that allowed the tracking team to follow its flight.

“With our first launch, it was a little bit windy, but eventually we found a spot that was a shielded from the wind, and everything went pretty smoothly,” Dobbs said. “We had some unexpected fogging on the lens above 35,000 feet that produced problems with the camera’s autofocus. So there was some blurring in the middle of the images, but a lot of good, usable data on the periphery.”

On the second launch, the group’s flight-prediction software forecast that a launch from Lawrence would land in the middle of Kansas City, an urban area that could have hindered retrieval of the balloon and camera. So, at the last minute, the launch was moved to Topeka. This time, the images from the flight were more pristine.

Students used data from the flights to complete research projects.

“They looked at things like identifying building footprints, evaluating the percentage of impervious cover, which can relate to water quantity and quality issues,” Dobbs said. “Some students looked at a variety of images taken at different altitudes to characterize the atmospheric component of the images, because as you get higher and higher, the scattering of the atmosphere adds a component to the signal of the image.”

Through calculations of payload weight, the students planned for the balloons to climb at about 5 meters each second, with the volume of helium in the balloon doubling every 19,000 feet. At about 100,000 feet, the balloons were designed to burst and deploy a parachute that became more effective as the payload fell earthward and the atmosphere became denser. The first balloon landed in a pasture, the second in the Johnson County tree.

Although this was the first year that Dobbs has integrated a hands-on remote-sensing data collection project into his class, it won’t be the last.

“I think that the students had a great experience with the project, and I would anticipate a project like this with the next class,” said Dobbs.

Images and information about the project are available at projectgeohawk.blogspot.com.