Global Positioning System, or GPS, has become a commonplace technology in today’s world since it first became fully operational in the mid-1990s. Its role as a force-enhancer have also made it a viable target in a contested cyber-space domain.
“Many technologies utilize the benefits of GPS and other Global Navigation Satellite Systems. Though it is not the only source of navigation for U.S. Air Force platforms, GPS is integrated in the avionics of a lot of aircraft,” said Marcea Ascencio, 775th Test Squadron. “The impact of GPS denial is not black and white for Air Force technologies, but can have varied impacts on the navigation system in addition to trickle-down impacts to the other subsystems; weapons, radar, sensor fusion, and communication systems.”
To help prepare for an event in which GPS is denied or degraded, the 412th Test Wing hosted its second Developmental Test Navigation Festival, at Edwards Air Force Base, Calif., in the fall. DT NAVFEST 2019 allows engineers to gauge the effectiveness of various assets that rely on GPS when the system is down.
“The testing is important because for civilian and military safety; we need to know as much as possible about how to keep aircraft systems safe from the threat of electronic interference,” said David Sunga, 775th Test Squadron. Sunga served as a technical consultant during DT NAVFEST 2019.
Sunga explained how vulnerable GPS signals are due to the satellites’ distance to the surface of the Earth.
“The power of a satellite signal is much less than a quadrillionth of a watt; a quadrillion is 1 with 15 zeroes behind it,” Sunga said. “The small size of this signal makes it especially vulnerable to deliberate jamming.”
The first DT NAVFEST event was held in 2017 and DT NAVFEST 2019 was only its second iteration. Conducting the event is a logistical challenge due to the number of other outside agencies involved and costs. Due to the possibility of local communities being affected by a lack of GPS signal, prior coordination has to be conducted. The event was tied in with an Orange Flag exercise at the time to stress systems in a very real-world scenario, Ascencio said.
Prior to the event, the Federal Aviation Administration had to notify all aircraft relying on GPS that testing may result in an unreliable or unavailable GPS signal within a 248-nautical-mile radius of Palmdale, Calif., when at 40,000 feet Mean Sea Level and 206 nautical miles when at 25,000 feet MSL. Local emergency services were also alerted.
“Performing this type of testing is costly and logistically challenging. By pulling together multiple participants, the cost can be split and the aircraft can participate at the same time, overall reducing the impact on the surrounding community,” Ascencio said. “Specific to this iteration of DT NAVFEST, the 412th Test Wing was interested in combining the Orange Flag with DT NAVFEST. These Orange Flag events have been critical to testing our interoperability capability with other air, land, and sea participants from the Air Force, Navy, Marine Corps and Army.”
More than 20 aircraft participated in DT NAVFEST and included participants from other branches as well as universities such as Auburn, Stanford, University of California Irvine and University of Colorado Boulder. The testing was conducted at night to mitigate impact to emergency services, civilian aircraft and population. The 412th Test Wing worked with the 746th Test Squadron from Holloman Air Force Base, N.M., who provided the assets necessary to create a GPS jamming environment.
“Since jamming testing is often too expensive, difficult, and infrequent to do for a single customer, we provide an event where multiple customers can chip in and participate, making testing affordable for all,” Sunga said. “These customers may have various goals in mind: research, training, developmental test of new technology and so on.”
Following the event, participants then have to analyze the data they collected and see the impact of GPS jamming had on their system, the data then flows back to the respective program office, and then gets addressed with either a re-design of the system or an update to the tactics for the user, Ascencio explained.
“From this event, participants were able to verify expected performance of their systems in these types of environments, uncover deficiencies, complete unique testing requirements that they have been not been able to accomplish via other methods, save money for tight budget programs, and help provide data to accelerate the fielding recommendations for systems under test,” she said. “Overall, the 412th Test Wing will continue to hosts these events, growing from the programmatic and technical lessons learned to make these events more accessible, effective, and useful for the warfighter.”