"iiCould the next big trading glitch come from the sky? An expert in satellite technology says it’s possible, and he wants more traders and investors to be aware of the potential problem. The danger lies with the global positioning satellite system, according to Todd Humphreys, a professor of aerospace engineering and engineering mechanics at the University of Texas at Austin. High frequency traders depend on GPS technology for accurate time signals to guide their trading strategies, but the satellite system’s rooftop receivers are vulnerable to jamming, he contends. GPS signals can also become the target of hacking attacks, known as “spoofing,” that can send out false time signals and disrupt trading, he adds."

Continue reading the Institutional Investor article.


gaoThe GAO Report to Congressional Requestors titled "Unmanned Aircraft Systems" notes that: 

"GPS spoofing has also been identified as an emerging issue. Encrypting civil GPS signals could make it more difficult to “spoof” or counterfeit a GPS signal that could interfere with the navigation of a UAS. Non-military GPS signals, unlike military GPS signals, are not encrypted and transparency and predictability make them vulnerable to being counterfeited, or spoofed. In a GPS-spoofing scenario, the GPS signal going from the ground control station to the UAS is first counterfeited and then overpowered. Once the authentic (original) GPS signal is overpowered, the UAS is under the control of the “spoofer.” This type of scenario was recently demonstrated by researchers at the University of Texas at Austin at the behest of DHS. During the demonstration at the White Sands Missile Range, researchers spoofed one element of the unencrypted GPS signal of a fairly sophisticated small UAS (mini- helicopter) and induced it to plummet toward the desert floor. The research team found that it was straightforward to mount an intermediate- level spoofing attack, such as controlling the altitude of the UAS, but difficult and expensive to mount a more sophisticated attack. The research team recommended that spoof-resistant navigation systems be required on UAS exceeding 18 pounds."

Continue reading the GAO report (GAO-12-981).

"While the Iranian capture of the Sentinel caught public attention, it also allowed researchers to show that spoofing technology has been, and continues to be, closely investigated by a number of military and civilian facilities in the United States.

Probably the leading–or at least the most public–GPS spoofing research center in the U.S. is at the University of Texas at Austin. In April, in response to a Department of Homeland Security (DHS) invitation, a University of Texas team took a commercial unmanned helicopter of the type used by police departments to the DoD White Sands, N.M. proving ground, along with the University’s GPS spoofing system. The helicopter was equipped with an autoflight system directed through GPS inputs, but with a manual control override."

Continue reading the Aviation International News article.


Austin, TX—Assistant Professor Todd E. Humphreys has been selected to receive the prestigious 2012 Regents’ Outstanding Teaching Award from The University of Texas System.

Established in 2008, the awards are offered annually in recognition of faculty members of the nine University of Texas System academic institutions who have demonstrated extraordinary classroom performance and innovation in undergraduate instruction, and are the Board of Regents’ highest honor.

“Professor Humphreys is a truly special case, “ASE/EM Department Chair, Professor Philip Varghese said. “He joined UT a couple of years ago and has excelled in teaching and in every other respect. He has significantly overhauled two undergraduate courses, making them more engaging and, probably, more demanding. Despite the rigor of his courses, he has stellar teaching evaluations in both graduate and undergraduate courses.”

Continue reading the ASE article.

For more information about the award and a video tribute to the awardees, please click here.

"aviationweekEase with which GPS can be spoofed raises concerns about civil UAVs. A video fo a small unmanned heicopter dropping from hover like a stone, its operator unaware control has been hijacked, threatens plans to open civil airspace to UAS (unmanned aerial systems) by exposing the vulnerability of GPS to counterfeit signals, or spoofing."

Continue reading the Aviation Week and Space Technology article that features an interview with Dr. Humphreys.

"eetimesAfter testifying before Congress about security vulnerabilities in civil GPS systems last week, Todd Humphreys is convinced the industry needs a new approach to plugging holes in what he calls “the most popular unauthenticated protocol in the world.”

“There’s a way to add backward-compatible authentication like digital watermarks to GPS signals, and last week I had my best shot at convincing lawmakers to fix the problem at the signal source,” said Humphreys who directs the Radionavigation Laboratory at the University of Texas at Austin."

Continue reading the EE Times article.


Washington, DC—Dr. Humphreys testified before the House Homeland Security Subcommittee on Oversight, Investigations and Management on the threat of spoofing the civil GPS signals that guide unmanned aerial vehicles in flight.

The oral testimony can be viewed online here.  Dr. Humphreys testimony begins at 11:00.

A copy of the written testimony can be read here.

"marinetimesA University of Texas team spent less than $1,000 to construct a GPS “spoofing” device that commandeered an unmanned aerial vehicle and sent it veering off course. After initially demonstrating the concept on campus in Austin, Assistant Professor Todd Humphreys and his team were invited out to White Sands, N.M., on June 19 by skeptical Department of Homeland Security officials and proved that they were able to divert a UAV from its flight path from about a kilometer away, according to a university news release. “The recent demonstration by University of Texas at Austin researchers is the first known unequivocal demonstration that commandeering a UAV via GPS spoofing is technically feasible,” the release states."

Continue reading the Marine Corps Times article.

"bloombergbusinessweekOne of the greatest advantages of drones—for gathering intelligence, patrolling borders, doing weather research, or killing terrorists—is that they can be piloted by people who are on the ground and far away. They can do dangerous, difficult, tedious tasks without requiring the risk of human lives. For their critics, there is a flip side to this: Drones risk making it too easy to kill without perceived consequences, or spy, or monitor every instant of everyone’s lives. Now there’s something new to worry about. If we can control our drones at a distance, what’s to ensure that someone else won’t do it, too? How easy would it be for someone to hijack a drone and Svengali-like, get it to do what they wanted, instead of its mission? Not as hard as one might hope. That’s what a team led by Todd Humphreys, an assistant professor at the University of Texas, Austin, and head of its Radionavigation Laboratory, proved last month."

Continue Reading the Bloomber Businessweek Technology article.

"abcGraduate students from the University of Texas who hijacked a civilian drone aircraft have demonstrated just how easy it would be to redirect unmanned vehicles—so-called UAVs that someday may do everything from delivering pizza to our doorstep to tracking stolen cars and aiding law enforcement. The hijacking was done over White Sands, New Mexico, at the request of the U.S. Department of Homeland Security. Officials with the department wanted to know if the students could actually do it. They did. The department has been reluctant even to talk about it. And the professor behind the capture has mixed emotions."

Continue reading the ABC article.

"nprA professor at The University of Texas has figured out how to intercept drones while in flight. Todd Humphreys and his team taps into the GPS coordinates of a civilian drone and can alter the flight path, even land it. Weekends on All Things Considered host Guy Raz speaks with Humphreys about how he did it and the dangers that hacking can present."

Continue to NPR to listen to the radio interview.

"wiredOn the evening of June 19, a group of researchers from the University of Texas successfully hijacked a civilian drone at the White Sands Missile Range in New Mexico during a test organized by the Department of Homeland Security. The drone, an Adaptive Flight Hornet Mini, was hovering at around 60 feet, locked into a predetermined position guided by GPS. Then, with a device that cost around $1,000 and the help of sophisticated software that took four years to develop, the researchers sent a radio signal from a hilltop one kilometer away. In security lingo, they carried out a spoofing attack. “We fooled the UAV (Unmanned Aerial Vehicle) into thinking that it was rising straight up,” says Todd Humphreys, assistant professor at the Radionavigation Laboratory at the University of Texas."

Continue reading the WIRED Danger Room article.

Read a follow-up article published after the congressional hearing.

"cnnBy 2015, unmanned drones will be allowed in U.S. airspace, raising many questions about our national security and privacy. What some University of Texas researchers set out to prove was whether it took much effort to hack them. With just $1,000 worth of software, the group was able to successfully hijack a civilian drone. Dr. Todd Humphreys and his team of students first experimented at the University of Texas at Austin. Then, the team was asked to demonstrate the process for the Department of Homeland Security. Dr. Humphreys and graduate student Daniel Shepherd explain how they were able to hack into the drone, and what implications it has for our nation's safety."

Continue to CNN to watch the video interview with Daniel Shepard and Dr. Humphreys.

todd_drone"aasAfter a dress rehearsal at Royal-Memorial Stadium, University of Texas researchers traveled to New Mexico last month and demonstrated for U.S. Department of Homeland Security officials how an unmanned aerial vehicle, or drone, can be commandeered by hacking into its navigation system.

The technique, known as spoofing, created false Global Positioning System signals that tricked the drone's GPS receiver into steering a new course.

The Global Positioning System, which uses satellites and radio signals, is not encrypted for civilian uses, and that raises concern about the federal government's plan to permit thousands of drones in U.S. air space for commercial, law enforcement and university purposes, said Todd Humphreys, an assistant professor in UT's Cockrell School of Engineering. "The dirty fact is it's an open signal, and easily hacked," Humphreys said."

Continue reading the Austin American Statesman article.

"cbsThe use of drones is taking off in America. Local governments and private businesses see them as a cheap and effective way of maintaining an eye from the sky. But will the drones be fully under their control? A college professor and his students say not necessarily. A civilian drone aircraft was hijacked by Prof. Todd Humphreys and his graduate students at the University of Texas. They were able to hack into the GPS signals of the drone, not only manipulating its flight path while flying over White Sands, New Mexico, but later landing it. Humphreys told CBS News, "You can think of this as hijacking a plane from a distance. (It's) as if you're at the controls of the plane, because you've now captured the autopilot's sense of its own navigation solution. And you can manipulate it left or right, up or down."

Continue reading the CBS article that features a video interview with Dr. Humphreys.

"rtTodd Humphreys’ tale about hacking a civilian drone in front of the Department of Homeland Security has gone viral since he conducted the experiment last month. Now the assistant professor at the University of Texas explains his work to RT. In an interview with RT America this week, Todd Humphreys of the University of Texas at Austin’s Radionavigation Laboratory reveals that it only took a few researchers, around $1,000 in parts and some seriously smart software to send signals to an unmanned aerial vehicle’s GPS receiver, hijack the craft in mid-air and then have it do the department’s bidding—all right in front of Homeland Security agents."

Continue reading the RT article that features a video interview with Dr. Humphreys.

RT's video interview can also be viewed on YouTube.

"kutA University of Texas professor recently hacked into the GPS system of a drone aircraft and take control of it using less than $1,000 worth of equipment. The achievement may have implications for the future use of drones in the United States and abroad. Let’s say you’re hungry and you’ve craving a meal from your favorite restaurant. But instead of a delivery car pulling up to the curb, a drone lands at your front door. It could happen. Todd Humphreys of the Radionavigation Laboratory at UT Austin thinks so.

Continue reading the KUT article that features an audio interview with Dr. Humphreys.

"alcaladeThere are a few reasons for a Longhorn football practice to be moved—a tornado, hail, and fire come to mind—but a science experiment isn’t usually one of them. But it wasn’t just any science experiment that caused UT Athletics officials to relocate the Longhorns’ strength-training practice last week: it was a demo that revealed a new danger to our national security. “It was funny,” says Todd Humphreys, director of UT’s Radionavigation Lab. “We were doing this huge, unprecedented demo, and the students were most excited about the fact that they moved football practice for us.” Humphreys and a group of engineering students have dedicated their time to researching a powerful new GPS technology known as spoofing, through which one GPS signal is replaced by another.

Continue reading the Alcalde article.

"cselogoA University of Texas at Austin research team successfully demonstrated for the first time that the 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. Cockrell School of Engineering Assistant Professor Todd Humphreys and his students were invited by the U.S. Department of Homeland Security to attempt the demonstration in White Sands, New Mexico in late June. Using a small but sophisticated UAV along with hardware and software developed by Humphreys and his students, the research team repeatedly overtook navigational signals going to the GPS-guided vehicle.

Continue reading the UT Engineering article.

slashdot"The BBC is reporting that researchers from the University of Texas at Austin managed to hack an experimental drone by spoofing GPS signals. Theoretically, this would allow the hackers to direct the drone to coordinates of their choosing. 'The spoofed drone used an unencrypted GPS signal, which is normally used by civilian planes, says Noel Sharkey, co-founder of the International Committee for Robot Arms Control. "It's easy to spoof an unencrypted drone. Anybody technically skilled could do this - it would cost them some £700 for the equipment and that's it," he told BBC News. "It's very dangerous - if a drone is being directed somewhere using its GPS, [a spoofer] can make it think it's somewhere else and make it crash into a building, or crash somewhere else, or just steal it and fill it with explosives and direct somewhere. But the big worry is — it also means that it wouldn't be too hard for [a very skilled person] to work out how to un-encrypt military drones and spoof them, and that could be extremely dangerous because they could turn them on the wrong people."

Continue reading the Slashdot article.

bbc"American researchers took control of a flying drone by hacking into its GPS system - acting on a $1,000 (£640) dare from the US Department of Homeland Security (DHS). A University of Texas at Austin team used "spoofing" - a technique where the drone mistakes the signal from hackers for the one sent from GPS satellites. The same method may have been used to bring down a US drone in Iran in 2011. Analysts say that the demo shows the potential danger of using drones."

Continue reading the BBC article.

Listen to the three-minute-long podcast interview with Dr. Humphreys starting at 49:30.

"spectrumResearchers at the University of Texas at Austin Radionavigation Laboratory have successfully demonstrated that a drone with an unencrypted GPS system can be taken over by a person wielding a GPS spoofing device. You can see a video accompanying a Fox News story on it, as well as a video here of an experiment conducted by the researchers, led by Professor Todd Humphreys.

Humphreys and company were recently invited by the U.S. Department of Homeland Security (DHS) to demonstrate whether their capability to successfully spoof commercial GPS systems in the laboratory could work in the field. Spoofing, as defined in this article by UT researchers, is “the transmission of matched-GPS-signal-structure interference in an attempt to commandeer the tracking loops of a victim receiver and thereby manipulate the receiver’s timing or navigation solution. A spoofer can transmit its counterfeit signals from a stand-off distance of several hundred meters or it can be co-located with its victim.”

Continue reading the IEEE Spectrum Risk Factor blog post.

Listen to an audio interview with Dr. Humphreys.

foxnews"A small surveillance drone flies over an Austin stadium, diligently following a series of GPS waypoints that have been programmed into its flight computer. By all appearances, the mission is routine.

Suddenly, the drone veers dramatically off course, careering eastward from its intended flight path. A few moments later, it is clear something is seriously wrong as the drone makes a hard right turn, streaking toward the south. Then, as if some phantom has given the drone a self-destruct order, it hurtles toward the ground. Just a few feet from certain catastrophe, a safety pilot with a radio control saves the drone from crashing into the field.

From the sidelines, there are smiles all around over this near-disaster. Professor Todd Humphreys and his team at the University of Texas at Austin's Radionavigation Laboratory have just completed a successful experiment: illuminating a gaping hole in the government’s plan to open US airspace to thousands of drones.

They could be turned into weapons.

Continue reading and watching the FoxNews coverage:

Myrtle Beach, SC—Two RNL members won conference-level best paper awards at the 2012 IEEE/ION PLANS conference. Congratulations to Jahshan and Ken!


Ken Pesyna (left) and Jahshan Bhatti (right) receive their Best Paper awards from IEEE/ION PLANS Committee Chair Wayne Soheren (center). 

"New York—I always knew I could lose my shirt on Wall Street, but I never thought I'd have to worry about my watch. Not the Rolex, but the actual seconds marking the passage of time. It turns out the sands of the hourglass that tell us when things such as stocks and bonds get traded can be stolen. Don't believe me? I've spent real time with the man who may have snapped time's Master Lock: Todd Humphreys, a professor of aerospace engineering and engineering mechanics at the University of Texas at Austin."

Continue reading the The Street article that features an interview with Dr. Humphreys.

"As our dependence on navigation satellites for accurate positioning and timing becomes ever greater, so do the natural and man-made threats that could compromise their usefulness."

Continue reading the GEO Connexion International artice: page one and two.

lemonde"In his small workshop cluttered with machines of all kinds, Todd Humphreys, director of the Radionavigation at the University of Texas at Austin, shows a video his students made of a recent test. It shows a smartphone, held at arm's length, showing Google Maps on the screen: "The device locates its position with GPS and indicates its position with a blue dot on the map." Suddenly, the blue dot starts to move, as if the smartphone were riding in a car, but the actual smartphone stays in the same place. "

Continue reading Le Monde article  [French].

bloomberg"Two years ago, a new global positioning system-based system guiding jets to runways at Newark Liberty International Airport began switching off without warning. The culprits, according to government documents, were drivers on the adjacent New Jersey Turnpike who were using cheap, illegal GPS jamming devices to prevent their employers from locating them. The devices, whose signals are as much as 1 billion times more powerful than GPS transmissions, were also blanking out the airport landing system. That passing vehicles could so easily cripple airport navigation illustrates one of the U.S. Federal Aviation Administration’s obstacles in its $42 billion effort, known as NextGen, to convert the nation’s air-traffic control away from radar to a reliance on GPS. Wireless networks, financial institutions and power grids are also vulnerable to GPS disruption, according to studies commissioned by the U.S. government and academic experts. “The interference threats to GPS are very real and promise to get worse,” the National Space-Based Positioning, Navigation and Timing Advisory Board, which is appointed by the government, said in a 2010 report. So-called spoofers may be a greater threat than jammers. They mimic signals from space and can trick a receiver into displaying the wrong location, Todd Humphreys, an assistant engineering professor at the University of Texas, said in phone interviews. “The mischief makers are looking for opportunities to prick us in our soft spots,” he said. “This is a soft spot and a pretty glaring one.”

Continue reading the Bloomberg Government article.

Watch the video news release.


Austin, TX — Daniel Shepard and Sydney Norrell offered visitors to the UT campus a chance to get hands on with high-tech GPS receiver processing during Explore UT, the biggest open house in Texas. The RNL exhibit featured a chance to draw 3D shapes and figures with a GPS antenna that were then displayed on screen. The GPS signal processing leveraged an advanced signal processing technique called carrier-phase differential GPS.

TEDxAustinPhototedAustin, TX — What's the predictable endpoint of the trend toward ever cheaper, ever smaller, and ever more sensitive GPS?  It's the GPS dot: a GPS tracking device first featured in the movie "The Da Vinci code" and now moving inexorably from fiction to non-fiction.  The GPS dot will fundamentally re-order our lives.  We'll buy dots in bulk and stick them on everything we own worth more than a few tens of dollars.

But there is a dark side to the dot.  Did you know that it's not illegal to track your family, your friends, or even your ex-girlfriend/boyfriend with a GPS dot?  The lack of effective legal means of protecting ourselves from an invasion of GPS dots will lead to use of subversive tools for protecting our personal space, such as GPS jammers and spoofers.  A rise in the use of these illicit tools has the potential to wreak havoc on the "good" GPS receivers -- those built into our critical systems and infrastructure. The result: A looming showdown between privacy and GPS integrity.

What if you could use GPS technology to find your misplaced keys? How about if you could use that same technology to lie about where you were in the world or misdirect cruise ships? Dr. Todd Humphreys of the University of Texas at Austin's Radionavigation Lab paints a picture of an utterly new future at once worrying and fascinating.

Check out the following TEDxAustin coverage:

"arstechnicaDuring the GNSS Vulnerability 2012 event at the UK's National Physical Laboratory on Wednesday, experts discussed the threat posed by a growing number of GPS jamming and spoofing devices. The increasing popularity of the jammers is troubling, according to conference organizer Bob Cockshott, because even low-power GPS jammers pose a significant threat to cell phone systems, parts of the electrical grid, and the safety of drivers."

Continue reading the Ars Technica article, which features an interview with Dr. Humphreys on spoofing.

"bbcThe illegal use of Global Positioning System (GPS) jammers in the UK has been revealed in a groundbreaking study. GPS jammers are believed to be mostly used by people driving vehicles fitted with tracking devices in order to mask their whereabouts. In one location the Sentinel study recorded more than 60 GPS jamming incidents in six months. The research follows concern that jammers could interfere with critical systems which rely on GPS."

Continue reading the BBC article, which features an audio interview (@3:35) with Dr. Humphreys.

"zdnetThe Sentinel project, which has been running since January 2011, was designed to measure GPS jamming on UK roads. The project, run by GPS-tracking company Chronos Technology, picked up the illegal jamming incidents via four GPS sensors in trials lasting from two to six months per location."

Continue reading the ZDNet article, which features an interview with Dr. Humphreys.

"wsjGPS signals are being routinely jammed by devices that can be bought online for little money. While most jamming is not serious, there is the potential for criminals to block, or even fake, GPS signals, a conference will be told Wednesday. The evidence of illegal jamming in the U.K. comes from roadside monitoring carried out by the SENTINEL project, which looks at whether satellite navigation systems including GPS can be trusted by their users."

Continue reading the WSJ article, which features an interview with Dr. Humphreys.

"insidegnssThis free one-day event at the British National Physical Laboratory in Teddington (London) on Wednesday, February 22 will present results of current jamming detection, and consider emerging threats such as meaconing and spoofing.The seminar runs from 9:30 a.m. to 5:30 p.m.

Interested participants must pre-register online.

Todd Humphreys, director of the Radionavigation Laboratory at the University of Texas-Austin will deliver the keynote, "PVT security: privacy and trustworthiness."

Continue reading the InsideGNSS article.

"theengineerShips colliding at sea, stock markets crashing, transport networks in chaos: these are some of the nightmare scenarios that researchers studying GPS-jamming techniques this week warned we could be facing if suitable countermeasures aren’t produced. The newspapers gave substantial coverage on Wednesday to a conference at the National Physical Laboratory (NPL) in west London, which highlighted the dangers society is facing as we become increasingly dependent on global navigation satellite systems (GNSS) like America’s GPS and the forthcoming European Galileo.

The problem is that GNSS satellite transmissions, which are used not just for navigation but also to provide time stamps for transactions at the stock market and to alert trains when to stop at specific stations, can easily be jammed or falsified (spoofed) with fake signals."

Continue reading The Engineer article, which features an interview with Dr. Humphreys.

foxnews"The Global Positioning System guides our ships at sea. It’s the centerpiece of the new next-gen air traffic control system. It even timestamps the millions of financial transactions made across the world each and every day. And it's at extreme risk from criminals, terrorist organizations and rogue states—and even someone with a rudimentary GPS jammer that can be bought on the Internet for 50 bucks, said Todd Humphreys, an expert on GPS with the University of Texas.

“If you’re a rogue nation, or a terrorist network and you’d like to cause some large scale damage—perhaps not an explosion but more an economic attack against the United States—this is the kind of area that you might see as a soft spot,” he told Fox News."

Continue reading the Fox News article, which includes a nationally-televised interview with Dr. Humphreys.

wiredcouk"GPS "spoofers"—devices that create false GPS signals to fool receivers into thinking that they are at a different location or different time—could be used to defraud financial institutions, according to Todd Humphreys from the University of Texas. On an innocuous level, GPS spoofing can lead to the confusing of in-car GPS systems so that users think they are in a different location to their actual location. However, a more sinister use could be to interfere with the time-stamping systems used in high frequency trading."

Continue reading the Wired article.

reuters"Satelite navigation systems are at risk from criminals, terrorists or even just bored teenagers, with the potential to cause major incidents from maritime disasters to chaos in financial markets, leading experts warned on Wednesday. From maps on car dashboards and mobile phones, to road tolls, aviation and marine navigation systems and even financial exchanges, much of modern life relies on Global Navigation Satelite Systems (GNSS) that use satelite signals to find a location or keep exact time."

Continue reading the Reuters article, which features an interview with Dr. Humphreys on GPS spoofing.

The article has also been published by DailyMail, Yahoo! Finance, MSN, The Baltimore Sun, CNBC, International Business Times, and Chicago Tribune.

Austin, TX — Kyle Wesson, Daniel Shepard, and Todd Humphreys authored the cover story of GPS World on anti-spoofing techniques for civil GPS in the January 2012 edition.

gpsworldThe introduction reads, "Disruption created by intentional generation of fake GPS signals could have serious economic consequences. This article discusses how typical civil GPS receivers respond to an advanced civil GPS spoofing attack, and four techniques to counter such attacks: spread-spectrum security codes, navigation message authentication, dual-receiver correlation of military signals, and vestigial signal defense. Unfortunately, any kind of anti-spoofing, however necessary, is a tough sell."

The story is online in flash or pdf format.

"wiredTake everything that Iran says about its captured U.S. drone with a grain of salt. But its new claim that it spoofed the drone’s navigational controls isn’t implausible. Although it’s way harder to do than the Iranian boast suggests, it points to yet another flaw with America’s fleet of robot warplanes."

Continue reading the WIRED article, which features an interview with Dr. Humphreys on GPS spoofing.

Austin, TX — zakThe Radionavigation Laboratory congratulates Zaher (Zak) Kassas for being elevated to IEEE Senior Member in 2011. To be eligible for IEEE Senior Member status, an IEEE Member must:

  • have experience reflecting professional maturity;
  • have been in professional practice for at least ten years; and
  • show significant performance over a period of at least five of their years in professional practice.

Zak Kassas is co-advised by Dr. Ari Araposthathis and Dr. Todd Humphreys.

Austin, TX — kenThe Radionavigation Laboratory congratulates Ken Pesyna for being selected to receive the Innovative Signals Analysis Fellowship for the 2011-2012 academic year. The fellowship comes with a $4,000 stipend.

In addition to being a member of the Radionavigation Laboratory, Ken is a member of the Wireless Systems Innovation Laboratory under the supervision of Dr. Robert Heath.


Boston, MA — MIT Professor Dr. Kerri Cahoy, cahoyan expert in radio occultation, invited Dr. Todd Humphreys to present on development of the FOTON GPS radio occultation receiver. The presentation was an Invited Enrichment Lecture for her graduate-level Satellite Engineering class and other students and faculty of the MIT AeroAstro department.

Coincident with Dr. Humphreys's visit, students Ingrid Beerer, Clayton Crail, Jason Herrera, Robert Legge, Whitney Lohmeyer, and Annie Marinan from Dr. Cahoy's Satellite Engineering course presented the final report of their semester-long feasibility study for the GeoScan Project. The students gave an excellent overview of all the sensors that they hope to pack into the hosted payload bay of the 66 IridiumNext satellites, which will begin to be launched in 2015. A GPS-based occultation sensor is one of the primary system sensor instruments proposed for GeoScan. Lars Dyrud, who has been the primary organizer of GeoScan project, was in attendance. Program directors from NSF attended the students' presentation virtually.



Portland, OR — Dr. Todd Humphreys chaired an ION GNSS 2011 panel session on "Improving Security of GNSS Receivers." Dr. Humphreys began the panel with introductory remarks [pptx] noting the increasing trend of spoofing research over the past few years and also presented on practical cryptographic civil GPS signal authentication [pptx]. The panel consisted of five members from industry and academia:

Austin, TX — Outside of the four papers contributed solely by RNL to ION GNSS, RNL members were co-authors on four other papers:

RNL at ION GNSS 2011

Portland, OR — Six members of RNL attended ION GNSS 2011 in Portland, Oregon to present research. Four papers were presented:

The last paper, which Kyle Wesson presented, won the best presentation award in Session E4: Next Generation GNSS Integrity 1.

At right: Members of RNL are about to enjoy a sushi dinner following the conference. Left to right: Zak Kassas, Daniel Shepard, Todd Humphreys, Jahshan Bhatti, Kyle Wesson, Ken Pesyna, and Ryan Mitch (Cornell). 

Whether it's investigating ways to preserve the security of GPS signals or developing new types of receivers, the field of radionavigation is ripe with possibility—and Dr. Todd Humphreys does not hesitate for a moment in defining how his research team fits into the mix. "What's the next big thing in GPS?" he asks. "That's what we're trying to pursue. In fact, that's what we're trying to create."

Continue reading the Aerospace Engineering Feature.


Austin, TX — Dr. Todd Humphreys briefed the United States Patent and Trademark Office via webcast on the state of the art and future trends in radionavigation on Thursday, 14 April 2011. Examiners were present from the main USPTO site as well as satellite locations. Dr. Humphreys talked about:

  • Overview of Radionavigation/GPS
  • Advances in Weak-Signal GNSS Tracking and Indoor Navigation + Network-aided Navigation
  • Vector Tracking for Improved Navigation Accuracy and Robustness
  • Multipath Mitigation

You can download and view the presentation here [pptx].

You can read more about the presentation here.

psiakia Austin, TX — Dr. Mark Psiaki visited RNL on 31 March and 1 April and gave two presentations:

  1. Nonlinear Model-Based Estimation Algorithms: Tutorial and Recent Developments [ppt] (BSEKF journal paper) at the Aerospace Department seminar series
  2. Civilian GPS Spoofing Detection based on Dual-Receiver Correlation of Military Signals [pptx] at the WNCG seminar series

UPDATE: Dr. Psiaki has written a paper on the Blind Tricyclist non-linear estimation problem available here [pdf]. Simulation functions and data are also available online.


Austin, TX — Members of the Radionavigation Laboratory briefed visitors from the DHS, USCG, NSWC, JNWC, and USSTRATCOM on several aspects of GPS security and integrity including: effects of GPS spoofing on power grid monitoring, anti-spoofing techniques for civil GPS, and GPS interference detection and localization techniques.

Meeting Agenda and Participants 

"Signals from GPS satellites now help you to call your mother, power your home, and even land your plane—but a cheap plastic box can jam it all."

Continue reading the NewScientist article, which features a discussion with Dr. Humphreys on GPS spoofing in the "Faking It" section. 

Austin, TX — Members of the Radionavigation Laboratory launched a memorial page for Dr. Paul M. Kintner, Jr. along with Paul's receiver, a continuously operating receiver in the spirit of an eternal flame. We started Paul's receiver running this month. We intend to keep it going as long as we can.

More tributes to Paul are welcome; please submit them to This email address is being protected from spambots. You need JavaScript enabled to view it.

Austin, TX — Members of the Radionavigation Laboratory went on a full day excursion to capture simultaneous GPS and Cellular CDMA spectrum via the lab's powerful National Instruments radio frequency signal analyzers. Over 1.5 TB of spectral data were recorded at 37.5 MSps with the goal of characterizing dynamic GPS multipath, exploring tightly-coupled opportunistic navigation, and evaluating GPS jamming mitigation techniques. The data log files are available here for download. Interested parties can request this data for their own post processing needs.

For a visual representation of the multipath encounterd, the data can be plotted in Google maps/earth. To see the visuals:
1) go to the test listing.
2) copy the "http:.// ... .kml?rand=99" URL of the test to map
3) open Google maps and paste the URL in the search bar


wardriving2 wardriving

"GPS timing signals that control the base stations in some cellular networks and other gadgets the size of small refrigerators that power the smart electric grid can fall prey to sophisticated spoofing attacks, according to a University of Texas researcher. Todd Humphreys, an assistant professor at the University of Texas Radionavigation Laboratory, said he successfully spoofed a type of laboratory time reference receiver of the code division multiple access network technology Sprint and Verizon use that relies on GPS time—with a transmitter he built for about $1,000."

Continue reading the Nextgov article.

"Here's a story to send a shiver down the spine of anyone who relies on their GPS sat nav or mobile. Scientists at Cornell University have managed to trick a GPS receiver into accepting signals from rogue transmitters instead of the genuine orbiting satellites."

Continue reading the TechRadar article.

"A paper presented by Cornell University and Virginia Tech researchers at this year's ION GNSS conference on the possibility of spoofing GPS has garnered mainstream attention."

Continue reading the GPS World article.

"Just like flat-screen televisions, cell phones and computers, global positioning system (GPS) technology is becoming something people can't imagine living without. So if such a ubiquitous system were to come under attack, would we be ready?"

Continue reading the ScienceDaily article

"With millions of GPS-based navigation devices on the road today, it is time someone considered the question: What if there’s an attack on the GPS network itself?"

Continue reading the WIRED Gadget Lab article.

"Computers have been hacked for decades. But now, scientists at Cornell University and Virginia Tech are now warning about the dangers of "spoofing," or hacking into the Global Positioning System (GPS) that controls everything from car navigation to national power grids."

Continue reading the Discovery News article.

"Computers have been hacked for decades. But now, scientists at Cornell University and Virginia Tech are now warning about the dangers of "spoofing," or hacking into the Global Positioning System (GPS) that controls everything from car navigation to national power grids."

Continue reading the MSNBC Article.

"The Global Positioning System (GPS) lies at the heart of an increasing number of technologies, from vehicle navigation systems to the power grid. And yet, although the military version of GPS includes security features such as encryption, civilian signals are transmitted in the clear. Now, researchers at Cornell University and Virginia Tech have demonstrated a relatively simple way to fool ordinary GPS receivers into accepting bogus signals using a briefcase-size transmitter."

Continute reading the MIT Technology Review article.

"Just like flat-screen televisions, cell phones and computers, global positioning system (GPS) technology is becoming something people can't imagine living without. So if such a ubiquitous system were to come under attack, would we be ready?"

Continue reading the Cornell Chronicle article.

Washington, D.C. — Dr. Humphreys briefed the National Space-Based Positioning, Navigation, and Timing (PNT) Executive Committee (EXCOM) Advisory Board on civil GPS spoofing. His presentation, "Spoofing the Timing Signal: What Else is Vulnerable? Understanding Potential Impacts to Infrastructure," highlighted the Radionavigation Lab's radionavigation security research including the RNL civil GPS spoofer (video) and a proposal for GNSS message authentication.


Background: The Global Positioning System has been a marvelous success over the past three decades. One consequence of this success is a deepening dependence of the civil infrastructure on GPS—especially for timing synchronization. As civil dependence on GPS grows, the potential for financial gain or high-profile mischief combine to make denial or manipulation of GPS a clear and present risk. European researchers and officials are as concerned about GNSS security as their U.S. counterparts. The launch of Galileo will not solve the navigation and timing security problem because, like civil GPS, the Galileo open service—projected to be by far the most commonly used—will be susceptible to jamming and spoofing.

Goals: European and U.S. researchers and interested observers met in Portland, Oregon in Sepetember 2010 to discuss civil navigation and timing security threats and strategize about (1) how policymakers and manufacturers can be persuaded to take these threats seriously, (2) how to identify effective countermeasures, and (3) how to promote adoption of effective countermeasures.

MeetingParticipants and Agenda

Opening Remarks: Todd Humphreys, The University of Texas at Austin

Overview of Vulnerability: Terence McGurn, consultant and PNT EXCOM Advisory Board member

Unique challenges involved in practical civil GNSS security: Todd Humphreys, The University of Texas at Austin

Video: Spoofing a Time Reference Receiver and Phasor Measurement Unit


Discussion Notes (provided by Brent Renfro, ARL)

Dr. Humphreys talked with the BBC radio show, "The Naked Scientists," about potential GNSS vulnerabilities.

Helen: So this sounds to me a little bit like when we had computers and we didn’t yet know anything about computer viruses. Almost that there’s a potential for someone to come along and mess around with the GPS and potentially cause some problems. But so far, we’re okay and the idea is that we should be pre-empting those problems

Todd: That’s right and the analogy with computers is a good one. There was a time, perhaps 20 years ago or more when we didn’t have to worry about computer security. But that time has passed and now we’re realizing that we must also pay attention to navigation and timing security.

Read or listen to the entire interview.