Army official: “We have struggled for years to codify and write a requirement for something as ubiquitous as PNT."

WASHINGTON — The Army is drafting new rules for the use of GPS receivers in weapon systems and will create a training program for soldiers that operate these systems. GPS provides position, navigation and timing information and the Army is looking for ways to make weapon systems more secure against electronic attacks aimed at GPS signals.

The Army’s goal is to protect systems and soldiers when they fight in “contested environments” where adversaries might attempt to disrupt GPS signals, said Willie Nelson, director of the Army’s assured positioning, navigation and timing cross-functional team.

GPS signals are susceptible to interference such as jamming and spoofing. Nelson’s office is writing a “capability development document” to address the meed for assured PNT, Nelson told reporters on Tuesday at the Association of the U.S. Army’s annual symposium. A CDD is where the Defense Department articulates the operational requirements of a weapon system.

“We have struggled for years in the Army to codify and write a requirement for something as ubiquitous as PNT,” Nelson said.

“GPS is embedded in just about every weapon system we have,” he said. The challenge was to “write a requirement for something a system needs but it’s hard to quantify.”

In the past the Army sought to write a “system of systems architecture for assured PNT,” he said. “We were not successful. It was too big and too broad.”

The new requirements document for GPS receivers is being broken down into three categories: mounted, dismounted and situational awareness. Mounted receivers are those installed in vehicles. The problem today is that an armored personnel carrier may have five to seven different GPS receivers that are not connected. Some have encryption, some don’t, Nelson said. “The weakest link of those receivers could potentially affect the whole vehicle.”

In new vehicles build from now on, the Army will require a consolidated PNT solution that is software based and can “drive all the other systems that need PNT in the vehicle,” he said. “We will have networked PNT instead of multiple systems.” The dismounted receivers used by soldiers also will have similar requirements.

Proposed PNT solutions will be evaluated and tested in experiments, he said.

The situational awareness piece is about making sure soldiers understand the threats they face and are prepared to react in case of an electronic attack. “With assured PNT we often think of it as a material solution.” But there are other considerations, he said. “How do we train our soldiers to fight in a degraded environment? Are we informing soldiers so they understand how a weapon system can perform under certain circumstances, and make sure they have tactics to work through the situation?”

Companies in the defense industry see assured PNT as a growing business as the military looks for equipment that can operate without GPS signals.

“Over the past two years there has been rising awareness of the weakness of GPS signals,” Jean-Yves Courtois, CEO of Orolia, told SpaceNews. The company specializes in assured PNT.

At AUSA, Orolia introduced a wearable combat search and rescue beacon designed to be used in covert military operations even when GPS signals are unavailable. It operates with a silent, push button that does not require voice activation.