Spoofing Risks Prompt Military to Update GPS Devices
Photo-illustration: Air Force, Getty
In 2011, Iranian citizens turned on their televisions to find the media zeroed in on a CIA drone allegedly captured by electronic warfare specialists who redirected the GPS coordinates of the system.
This was the first potential major incident of GPS interference on a U.S. government device, according to Dana Goward, president of the Resilient Navigation and Timing Foundation in Alexandria, Virginia. The following year, a professor at the University of Texas successfully redirected a government drone when challenged to do so by the Department of Homeland Security.
Being susceptible to spoofing and jamming is a risk of using GPS signals, Goward said. A signal can be “spoofed” by being replaced with false or misleading information, whereas jamming involves stopping or disrupting a signal. However, quantifying and verifying the number of these attempts can be difficult because perpetrators often aim to operate undetected, he noted.
The alleged CIA drone incident was the “coming out party” that brought these navigation risks to light, Goward said. Since then, there have been other episodes as well. The U.S. Maritime Administration in June 2017 reported that 20 ships in the Black Sea may have been victims of GPS interference. The Coast Guard has also announced experiencing potential jamming episodes.
However, technology has advanced to the point where state actors are no longer the only ones who are able to perform such operations, Goward noted. Now, it has trickled down to the “consumer bad guy level,” meaning that non-state actors can easily purchase the necessary equipment to interfere with GPS signals, he said.
Todd Humphreys, the professor who completed the challenge from the Department of Homeland Security, noted that it’s now possible to download the codes to generate spoofing signals from the internet.
“You can download a code that has been developed by a Chinese researcher and a Japanese researcher ... and put this onto [a] commercial-off-the-shelf radio frequency generation device,” he said.
Although the U.S. military still has GPS equipment that is more resilient than the average commercial device, they tend to be classified and “fairly difficult to use,” Goward said.
“We understand that folks in the military don’t use their military GPS equipment because it’s just a pain in the butt,” he said. Sometimes this leads to practices such as using commercial-off-the-shelf GPS devices rather than the required systems, he noted.
“Even though the military does have the equipment to counter some of the [risks], the usability of it and willingness to go through the trouble of using it can be a challenge,” he added.
To mitigate breaches, the armed services have turned to strengthening their navigation signals and investing in assured positioning, navigation and timing technology, which would allow operations to continue in GPS-denied environments.
The Navy has begun fielding its next-generation PNT distribution system, which is known as the GPS-based position, navigation and timing service, said Dan Brothers, deputy program manager for the Navy communications and GPS navigation program office. The system will serve as a “fusion device” that can compare and select data from multiple sensors, he said in an email. Some sensors on the equipment include inertial measurement units, speed logs and gyrocompasses.
Much of the equipment used by the Navy is employed by the Air Force as well, he added. That eases the process of developing technology by allowing the services to procure items on the same contract.
Brothers said his program office is currently maturing compact anti-jam systems that could be installed onto equipment such as unmanned aerial vehicles, naval surface platforms and military sealift command systems. The Navy plans to develop prototypes of these anti-jam devices and put them through environmental testing, he noted.
The Air Force has also been working to mitigate GPS spoofing and jamming by strengthening and updating its navigation signals, said Col. Steven Whitney, the director of the global positioning systems directorate at the Space and Missile Systems Center in Los Angeles.
“You can see that through the course of GPS history in the introduction of new signals,” he said. Courses of action include adding more civil signals as well as a new military signal called M-Code, he said.
The service is currently pursuing GPS III, a program that improves upon its predecessors by providing new civil and military signals and increased accuracy. Lockheed Martin is under contract to develop the initial batch of 10 systems, the first of which is scheduled to be available for launch in summer 2018.
The service is also holding a competition for the next set of GPS III satellites, which will have an added requirement to have a “regional military protect” capability, which means the “ability to jump the signal by [a] significant margin of about 10 to 13 direct broadcast satellites … over the baseline signal,” he said. Having higher power GPS signals can help “break through” and override potential interferences, Whitney noted.
The acquisition strategy for the next iteration of GPS will allow the Air Force to leverage new technologies and make changes to the production flow as needed, he noted.
“This would be essentially cost neutral because there would be improvements in capabilities and also improvements in efficiencies in how we produce,” he said.
Goward said GPS III will produce stronger signals, but it’s a “marginal improvement” that “is not going to solve things.”
Rep. John Garamendi, D-Calif., suggested adopting a robust backup system for domestic operations.
Together with Rep. Frank LoBiondo, R-N.J., Garamendi spearheaded a section in the fiscal year 2018 National Defense Authorization Act requiring the secretaries of defense, transportation and homeland security to develop a plan for a backup GPS capability demonstration, based on the results of a study mandated by previous legislation.
“Those three agencies will coordinate,” Garamendi said in an interview with National Defense. “The $10 million in the National Defense Authorization Act, and hopefully in the appropriations to follow, is to get this thing up and moving.”
Although the study is platform-agnostic, Garamendi stressed that researchers will outline the benefits of eLoran, an enhanced version of a ground-based navigation system formerly operated by the Coast Guard and later abandoned in 2009 in favor of GPS. The upgraded device functions in the frequency of 90 to 110 kilohertz and can be used over long distances.
eLoran would provide useful terrestrial signals, Garamendi said. “It’s a very strong, very low frequency signal that travels at very, very large distances. And while the Air Force does have a navigation system, that’s not [a] sufficient reason to not have the eLoran system also available,” he added.
To add the capability onto a smartphone, one would simply add the eLoran signal to the communications chip, he said.
The United States must be up to par with other countries that have already taken steps to beef up their navigation systems, he said, noting that Russia and China have already deployed devices similar to eLoran. Goward added that Russia’s doctrine states that it must be able to operate its equipment using land-based signals.
“The Russians believe ... that when they go to war, all signals from space will be blocked because it’s really easy to block signals from space — why would you not do that?” Goward said. “The Russians are right.”
While the U.S. military is aware of the risks associated with relying on GPS signals, each service has its own spending priorities, Garamendi noted.
“The military is on a march ... and in many cases, they’re not looking to the side and they’re not really considering what’s not happening. They’re dealing with today,” he said.
“I find this to be an ongoing problem in many, many ways and it’s clearly a problem in this area.”
Using eLoran would be an efficient employment of resources because the necessary sites, which were put into place during World War II, are still owned by the Coast Guard and Department of Homeland Security, he said.
However, these are domestic sites, and the U.S. military operates globally.
Goward said the Air Force previously had a deployable version of the Loran device in the 1970s and that an updated version could “easily” be developed for eLoran.
The Army has also acknowledged that it needs to prepare for GPS-degraded environments. The service’s assured positioning, navigation and timing program consists of a “systems of systems” that focuses on protecting access to navigation information and the ability to manage software modernization at the platform level, according to a statement from the Army’s PNT program manager.
There will be four systems in total “designed to work as an integrated capability with the goal to achieve assured PNT in nearly all GPS-challenged environments, across all formations and warfighting functions,” the statement said. The Army has an effort underway to develop a “quick reaction capability solution for select combat vehicles.”
Although this will be a limited effort under the Rapid Capabilities Office, it is expected to inform a larger enduring program as well, according to the service.