Spotlight

April 2021: The prevalence of unmanned aerial vehicles has caused a plethora of safety and regulatory problems in recent years, which is why several companies are developing counter-UAV technologies. Some of these use kinetic methods to disable offending drones, but others use microwave radiation to either jam or disable the drones’ onboard electronics. 

“A ray gun that can fry a drone’s electronics at hundreds of meters sounds like something Tony Stark would invent” says Dr. Humphreys. 

Amazing as it sounds, such devices are being developed today. But companies seeking to test their devices are being denied by the FCC and referred to the National Telecommunications and Information Administration (NTIA), which has jurisdiction over military spectrum experiments. Read the IEEE Spectrum article here.

March 2021: GPS interference has been a worsening problem for the past decade, particularly for aviation. This article from IEEE spectrum covers current research efforts to detect and monitor GPS interference. Data from ADS-B and terrestrial GPS receivers offer a good start, but Dr. Humphreys explains that these sources are limited by sensor sparsity: 

“There are fewer than 3000 GPS reference stations with publicly-accessible data across the globe; these can be separated by hundreds of miles. Likewise, global coverage by ships and planes is still sparse enough to make detection challenging, and localization nearly impossible, except around ports and airports.”

The Radionavigation Lab’s recent paper, GNSS Interference Monitoring from Low-Earth Orbit, shows how satellites in low-earth orbit (LEO) can be used to monitor terrestrial GPS interference. A network of GPS-monitoring satellites in LEO may be the solution to global detection and monitoring of GPS interference. 

January 2021: This recent article from The New York Times summarizes America’s extreme dependence on GPS and the resulting vulnerabilities. They credit Dr. Humphreys’s 2008 paper on GPS spoofing with bringing the weakness to light. When asked about the urgency of finding alternatives to GPS, Dr. Humphreys said

“If we don’t get good backups on line, then GPS is just a soft rib of ours, and we could be punched here very quickly.”

The article underscores several of the Radionavigation Lab’s research areas, including Russian GPS interference and maritime GPS spoofing.  

January 2021: FAA pilot reports have revealed that military tests are interfering with airline flights. The military is presumably generating GPS interference to test their latest positioning technology, but the interference is reaching beyond the test sites and jamming passenger aircraft that routinely rely on GPS for navigation and landing. Although pilots are trained for such scenarios, the loss of GPS is so rare that it can still cause disorientation and confusion in the cockpit. In this article from IEEE Spectrum, Dr. Humphreys explains: 

“I don’t blame pilots for getting a little addicted to GPS. When something works well 99.99 percent of the time, humans don’t do well in being vigilant for that 0.01 percent of the time that it doesn’t.”

October 2020: Check out our videos page for an update on the Radionavigation Lab’s research! We’ve been working hard to produce short video summaries of our recent papers. Enjoy!

• Multi-Antenna Vision-and-Inertial Aided CDGNSS for Micro Aerial Vehicle Pose Estimation
• Fused LEO GNSS
• Vehicle Sensorium Demonstration
• Open-World Virtual Reality Headset Tracking
• Game-Theoretic Counter-UAV for Real-World Situations
• All-Weather sub-50-cm Radar-Inertial Positioning
• A Proposal for Securing Terrestrial Radio-Navigation Systems
• Long Range, Low SWaP-C FMCW Radar

October 2020: This recent article from BBC explores the modern world’s dependence on GPS and some possible position, navigation, and timing alternatives. We depend on GPS for everything from turn-by-turn navigation to banking transactions, but the system has some critical vulnerabilities to jamming and spoofing.

“There is a growing recognition of the need to protect, toughen, and augment GPS,” Humphreys said, “There is also the remote threat that the whole GPS constellation could be rendered inoperable in the initial salvo of a war targeting the US economy by attacking critical infrastructure.”

Many research groups are developing possible alternatives like terrestrial, inertial, and even celestial navigation, but none of these have been able to fully replace GPS. 

October 2020: Dr. Peter Iannucci’s recently-submitted paper, Fused Low-Earth-Orbit GNSS, was highlighted in the MIT technology review for its expected impact on the US Army’s navigation technologies. The paper proposes to leverage low-earth-orbit internet constellations, like SpaceX’s Starlink, to provide strong, jam-resistant positioning signals that augment the existing GPS. The need for this augmentation is emphasized by the recent emergence of low-cost GNSS jammers and spoofers, which have been appearing across the globe. Dr. Iannucci and his coauthor Dr. Humphreys are optimistic that this technology will prove indispensable for high-integrity navigation. 

Read the MIT Technology Review article here.

September 2020: The Department of Transportation recently allocated nearly 2 million dollars to fund a new University Transportation Center (UTC) whose members include Ohio State University, the University of California Irvine, and the University of Texas at Austin. Dr. Zak Kassas, an RNL alumnus, is the Principal Investigator of the overall multi-university center. Dr. Humphreys will lead the center’s effort at UT Austin. “We beat out at least a dozen other teams vying for this UTC,” Humphreys explains. The UTC will focus research on highly-automated transportation systems, with an emphasis on safety, security, and reliability. Read the full article here.

September 2020: NASA recently started accepting commercial contracts for missions to the International Space Station (ISS). Initially intended to make the ISS more accessible to scientific companies, the new initiative is attracting unexpected clients. NASA astronauts will soon be tasked with filming cosmetics commercials and transporting souvenirs. Dr. Todd Humphreys comments on this development, saying “If the circus is necessary to maintain the International Space Station, it’s probably a good trade-off.” 

Read the New Scientist article here.

August 2020: Dr. Todd Humphreys’s groundbreaking work in GPS over the past decade was featured in this article from the New Yorker. The article offers a charming summary of Dr. Humphreys’s career and the Radionavigation Lab’s GPS-related research.