Sales of hand-held systems such as Rockwell Collins' defense advanced GPS receiver are declining, but efforts to give troops protected GPS capabilities are picking up steam. (Rockwell Collins)
WASHINGTON — The US Defense Department is looking for alternatives to GPS, techniques that can provide positioning data without the vulnerabilities satellite communication entails. But while they’re waiting for the technology to arrive, companies are looking at techniques to help better guard GPS signals, for both military and commercial applications around the world.
The two primary issues that companies are trying to sort out are jamming, where a powerful signal is used to disrupt a receiver’s ability to decipher the proper GPS link, and spoofing, where a system pretends to be another system.
“Everyone’s talking to us about alternatives to GPS,” said Al Simon, a marketing manager with Rockwell Collins. “But, there’s still a lot of opportunity to make GPS more robust so that you can rely on it if you have to go fight tomorrow. We see that probably still taking place for a while.”
Some of the protection techniques have been around for some time, although they’re getting a closer look and possibly additional applications. Using multiple frequencies and encrypted data allows the GPS receiver to filter through some of the unwanted signal problems, and it’s something Rockwell Collins has been doing for years on weapons systems, Simon said.
Now, with the increased use of GPS for troops on the ground and small UAVs, the company has been looking at ways to use the same techniques in a lightweight, low-power model.
“We’ve been doing it for years in the weapons arena, and we’re now finding the need to provide some of that capability to war-fighting elements,” Simon said. “It’s easier to implement in a weapon or an aircraft because you’ve got larger real estate to operate with.”
Implementing the technology also means keeping up with the US military’s drive for single-device solutions. The company used to sell quite a few hand-held defense advanced GPS receivers, although sales are down, Simon said. Now, Rockwell is looking at developing protected GPS solutions for other systems.
“You can sense that it’s starting to happen. The demand’s there. The technology is there. It’s something that there’s discussion about, so we’re already prototyping some stuff. We just haven’t gone to big production lines yet,” he said.
But because GPS has become so ubiquitous, the potential applications aren’t limited to global militaries. Commercial shipping, critical infrastructure, even pizza delivery can use GPS.
So Exelis is trying to tackle the jamming problem from the commercial side. The company spent its own research and development money to create Signal Sentry, a system that can locate the position of a jammer inside a protected area. Harming the jamming system has its own risks. So instead, the company emphasized the accuracy of Signal Sentry, pinpointing a jammer within 10 to 15 meters, allowing a user to take action.
To achieve that kind of accuracy, six to 10 antennas are set up around the perimeter of a protected area, and the relative power of the jammer as detected by those antennas allows the system to triangulate the jammer’s location.
While designed for the commercial market, Exelis does want to move the product into the military sphere, said Kevin Farrell, general manager of Exelis’ positioning, navigation and timing unit.
“We have a road map that takes us into military applications, but that’s not the focus of the initial rollout,” Farrell said.
One of the reasons for approaching the development of the system that way is to make sure that the company wouldn’t have any problems with exports. Because Signal Sentry was designed as a commercial item, it isn’t nearly as restricted as military items. Officials in Australia, Canada, South Korea and the UK have expressed interest.
But it’s also a sign of the times as far as US military budgets, said Joe Rolli, the program manager.
“Usually, our business model is that a customer comes to Exelis and we work with them to develop a product that meets their requirements,” Rolli said. “But in this changing environment, we can’t do business that way. We’ve got to find new ways to generate business.”