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Positioning, Navigation and Timing and What it Means for the Soldier

U.S. Army Spc. Christopher Quimbaya, a paratrooper assigned to 1st Battalion, 503rd Infantry Regiment, 173rd Infantry Brigade Combat Team (Airborne), uses a Defense Advanced GPS Receiver (DAGR) during a combined-arms live-fire exercise at Grafenwoehr, Germany, March 28, 2014.

U.S. Army Spc. Christopher Quimbaya, a paratrooper assigned to 1st Battalion, 503rd Infantry Regiment, 173rd Infantry Brigade Combat Team (Airborne), uses a Defense Advanced GPS Receiver (DAGR) during a combined-arms live-fire exercise at Grafenwoehr, Germany, March 28, 2014. (U.S. Army photo by Visual Information Specialist Markus Rauchenberger)

Imagine you’re driving to a vacation beach house, when suddenly your Global Positioning System (GPS) tells you that you’re veering off into the ocean. It’s obvious to you that you’re still on the road, a good mile or two away from the sea. Without warning, you’re navigating in the blind, unsure of your exact location or where you are in reference to your destination. Depending on how quickly you get your signal back, you could be drastically off-course, meaning you’ll need to re-route and your vacation will be delayed. In a world where we utilize GPS technology on a daily basis, scenarios such as these can be frustrating.

Now imagine you’re a soldier navigating a valley in Afghanistan. The same situation strikes – you lose your GPS signal and are now traveling in the blind – only you’re on a mission and veering off-course can result in dangerous consequences. When GPS satellite signals are impeded or denied in a combat environment, whether by terrain conditions or enemy interference, it inhibits troops’ ability to complete the mission. At best, the signal returns quickly. If not, it could leave soldiers vulnerable in hostile territory.

As Army forces increasingly operate in conditions that hinder or block access to GPS signals, it has become imperative to provide them trusted Positioning, Navigation and Timing (PNT) information through other means. Just last month, Secretary of the Army Nominee Eric Fanning emphasized the importance of secure PNT data to a modernized Armyto Congress at his confirmation hearing.

So what is PNT? How does it relate to GPS and why is it so important?

PNT data is used in countless military operations and GPS is one of the ways Soldiers receive PNT data on a mission, giving them a sense of their own location as well as the whereabouts of friendly and enemy forces. Unfortunately, GPS also has inherent vulnerabilities. If a Soldier loses the GPS satellite signal, his or her system can lose its PNT data. The Soldier no longer has the ability to recognize location and timing, meaning situational awareness has been compromised and the mission is now threatened.

To address this challenge, the Army’s Direct Reporting Program Manager Positioning, Navigation and Timing (PM PNT) is delivering innovative technologies that will augment and enhance GPS, giving Soldiers the ability to access accurate and trusted PNT information even when a GPS signal has been compromised. PM PNT leads the Army in developing and integrating PNT technology that will allow for the transmission of accurate and reliable PNT data, unhindered access to trusted PNT information, and continued access to GPS signals in challenged environments.

Two critical current Army PNT initiatives are the Assured PNT (A-PNT) program and the PNT System of Systems Architecture (SoSA). The A-PNT program is focused on providing a resilient PNT capability – meaning access to PNT data that our Soldiers can trust in contested environments. A-PNT brings non-GPS augmentation through state of the art technologies developed through the Defense Advanced Research Projects Agency and industry. However, the A-PNT approach involves not just materiel solutions (new hardware and software), but also includes that the Army’s architecture, training, testing and operational concepts evolve. With hundreds of different Army systems that require PNT data, the PNT SoSA guides and constrains the development of all Army system of systems consuming or providing PNT information to include upgrades across platforms and domains, thus reducing inefficiencies and redundancies, while decreasing vulnerabilities and outpacing changing threats.

In addition to A-PNT and the SoSA, the Army’s Communications Electronics Research, Development and Engineering Center (CERDEC) is developing additional technologies that will make future PNT systems more robust. Among these advancements are vision-aided navigation systems that will exploit data from cameras, as well as Light Detection and Ranging (LIDAR) systems that are already employed on the platform or Soldier to predict the platform’s direction and velocity. Radio Frequency (RF) ranging systems under evaluation by CERDEC will measure the distance between platforms and squad members. CERDEC is also evaluating off the shelf receivers for Signals of Opportunity (SoOP), or signals that are available in the battlefield for other purposes but can be used for position and orientation. To process information from these advanced sensors and receivers, CERDEC is developing sensor fusion technology that can adapt to changing terrain and electronic environments in order to produce a continuous robust PNT solution. Finally, CERDEC is developing advanced antenna and receiver electronics that will protect GPS in the presence of or unintended electronic interference from friendly force systems, as well as from enemy spoofing or jamming attempts.

Together, the PM PNT and CERDEC team will continue to advance resilient PNT capabilities that complement and enhance the GPS we rely on today. Thanks to these efforts, our Soldier positioned in a valley of Afghanistan – or any future operational environment – will be confident in his or her location, distance to the destination, estimated time of arrival, and ability to communicate, regardless of access to the sky.