The Global Positioning System (GPS) uses satellite radio waves to map restaurants on our smartphones, guide cars and monitor aircraft. For those who want to stop others from tracking their movement, GPS signals can be jammed -- albeit illegally. And now, GPS signals can also be "spoofed."
"A GPS spoofer, instead of just trying to jam the signal, tries to mimic [it]," says Todd Humphreys, a professor of Aerospace Engineering at the University of Texas, who spoke during a recent session at South by Southwest. "And if you can do this precisely enough, you can fool a receiver into tracking your [spoofed] signals instead of the authentic ones."
Humphreys and some of his students set out to test the possibility. They got an $80,000 pilotless aircraft -- a drone -- and flew it over an otherwise empty football stadium.
"The drone was commanded to hover in place, holding its position," says 23-year-old graduate student Daniel Shepard, who ran the experiment. The team then told the drone's GPS receiver that it wasn't hovering -- it was rising. "In response it plummeted towards the ground in rather dramatic fashion."
The demonstration got the attention of Congress and Homeland Security which unlocked some funding to try to protect the GPS system from spoofing.
To hear more about the possibility of GPS spoofing, click on the audio player above.