May 6, 2013
Aerospace engineering graduate student Daniel Shepard (BS ASE 11, MS ASE ’13) has been recognized for his research with faculty advisor Todd Humphreys.
Shepard is a recipient of the prestigious National Defense Science and Engineering Graduate (NDSEG) Fellowship, given to only ten percent of all applicants. It provides three years of support covering full tuition and fees, a monthly stipend and medical insurance. The NDSEG Fellowship was created by The Department of Defense (DoD) in an effort to increase the number and quality of America’s scientists and engineers.
Shepard has worked on two projects during his undergraduate and graduate career – GPS spoofing and an augmented reality system.
Along with Humphreys, Shepard is working on GPS spoofing, a project that holds significant implications for national security. GPS signals of an unmanned aerial vehicle (UAV), or drone, can be commandeered by an outside source — a discovery that could factor heavily into the implementation of a new federal mandate to allow thousands of civilian drones into the U.S. airspace by 2015.
The technique creates false civil GPS signals that trick the vehicle's GPS receiver into thinking nothing is amiss — even as it steers a new navigational course induced by the outside hacker. Because spoofing fools GPS receivers' on both their location and time, some fear that most GPS-reliant devices, infrastructure and markets are vulnerable to attacks. That fear was underscored — but not proven — when a U.S. military drone disappeared over Iran late last year and showed up a week later, intact, and in the care of Iranians who claimed to have brought the vehicle down with spoofing.
The second project Humphreys and Shepard are working on is creating a prototype of a high-precision augmented reality system. Augmented reality systems blend virtual elements and reality to improve understanding and enhance one’s experience. A high profile example of this is Google Glass, a pair of glasses that allow users to take pictures, use GPS, watch videos and more, through the lenses.
The two hope to develop a new navigation system for use in the augmented reality system to improve location and orientation accuracy. Most GPS devices use the standard positioning service (SPS). This method of positioning is only accurate to a range of a few meters. Methods used for determining orientation in most smart-phones, the most commonly used devices for augmented reality today, can typically only determine the direction the smart-phone is pointing to within a few degrees. But Humphreys and Shepard are combining several navigation techniques including carrier-phase differential GPS, visual-based navigation and an inertial navigation system (INS) in order to develop a more accurate system that can position a user to within an error of only a few millimeters and determine the direction the user is looking to within an error of less than a degree.
Construction and utility workers will greatly benefit from a high-precision augmented reality system. Often times, water and gas lines are broken because workers cannot locate their exact location. Even though there are databases that contain the utility lines’ locations, it is difficult to interpret and transfer that information precisely to the corresponding physical location. A high-precision augmented reality system will visually display the utility lines at their exact location.
Shepard attributes his well-rounded research experience with the vast amount of opportunities he has had since his days as an undergraduate student.
“It is unique that I get to do both theory and building actual systems,” Shepard said. “I am doing what I believe an engineer should – designing and building systems that have a lot of consumer applications.”
Shepard began his research as an undergraduate student and credits it to creating a positive graduate experience.
“UT is one of the top schools in the nation for engineering,” Shepard said. “It’s been a great experience for me. I took undergraduate classes with Dr. Humphreys, did my undergraduate honors thesis with him and spent my senior year working in the lab. It contributed to my experience in a lot of ways. I continued working in the lab as a graduate student and was able to hit the ground running with a remarkably productive first year of graduate studies since I was already familiar with the equipment and research.”
Shepard will begin his doctoral work this fall and hopes to enter the industry once he graduates.
