The U.S. Army, through its assured position, navigation and timing, or PNT, program, is trying to remedy this issue.
This program will take the Army to the next level of navigation warfare and PNT capability beyond just GPS alone, according to Kevin Coggins, the service's program manager for PNT. Speaking at the C4ISRNET Conference on May 3, Coggins said GPS is currently the gold standard for how to get PNT information.
Adversaries have figured out how to attack this technology, he said, noting that it has many vulnerabilities detailed in open-source materials for exploitation. Russia, especially in Syria, have been very effective at exploiting these vulnerabilities, Coggins asserted.
“We’re not used to operating in an information-contested environment,” Maj. Gen. Lori Reynolds offered at the same conference. The chief of the Marine Corps Forces Cyberspace command was referencing the last 15 years of war against technologically inferior adversaries.
Coggins conceded that the force must do better at assured PNT, which he called a complex system of systems, with GPS being just one component.
He provided a three-tiered approach to countering threats to PNT, from the lowest-level threats to the peer level. The easiest way to counter GPS signal jamming is to give soldiers on the ground situational awareness sensors so they can detect that piece of the electromagnetic spectrum and see the noise in that space. As jamming is a line-of-sight capability, the solider would take the receiver behind a building.
If this is impossible, chip-scale atomic clocks, which have become less costly, can be put into a device independent of GPS to allow electronic warfare systems, radios and the like to continue to function.
When dealing with more sophisticated adversaries that might have multiple jammers, more expensive complements such as anti-jam antennas might need to be brought into the fold.
With a near-peer or peer adversary, Coggins explained that secure radio frequency power technologies controlled from the ground rather than space are an option, though that route would also be expensive. The beauty of this, however, is that only a small number are needed, he said — not every soldier requires such a capability.
With threats to PNT and cyberspace, forces might have to revert to more primitive technologies when denied. Reynolds said she was encouraged when recently visiting Okinawa, Japan, for the III Marine Expeditionary Force exercise, as some in the division were using maps and single-channel radios.
“They know how to do that, and we used to do that all the time, and so bringing back those old skills and know that if all else fails,” Marines can use a single-channel radio, she said.
Similarly, Rear Adm. Dannell Barrett, director of Navy Cyber Security Division with the Office of the Chief of Naval Operations, said during the conference that one of the skills being taught at the Naval Academy is celestial navigation so that sailors don't rely on a computer if communications or GPS are denied.
“We are conscious about keeping costs down and being efficient. But there is a cost when you lose our ability to conduct fires or talk or maneuver. We’ve got to balance that out,” Coggins said.
He also noted that there will be three requests for information released in June within the assured PNT program, with an industry day to follow.