Building GPS OCX

The Next Generation Operational Control System


They may look like giant golf balls on the outside, but radomes - like this one in Colorado - are the primary link for systems like GPS OCX and the satellites they operate.

When a dependable technology you've come to rely on stops working, what do you do?

Civilian and military operations worldwide have grown dependent on a functioning GPS system. Guiding vehicles; aiding air traffic control systems; monitoring agricultural activities; providing geolocation for communications systems; synchronizing financial transactions — these and many more integral parts of the economic and day-to-day lives of more than 2 billion people worldwide rely on GPS.

The space-based piece of America's GPS system is made up of more than two dozen satellites orbiting the Earth. The satellites are controlled by a ground system that allows technicians to manage and operate the satellites, protect the data passing to and from users, and monitor the system's performance to ensure accuracy.

A high-performance vehicle without an intelligent driver is little more than a collection of expensive hardware. In many ways, the ground system functions as the “brain” of the entire GPS system.

And the current brain is showing its age. As such, it's incapable of using the full capabilities of GPS II satellites currently in orbit. And when the next generation of GPS III satellites are launched, they'll introduce even more technology the current ground system can't handle.

To solve this capability gap, the GPS Next Generation Operational Control System (GPS OCX) is currently in development. OCX modernizes the ground system, allowing it to take advantage of the updated capabilities of GPS II and GPS III satellites, and giving the system flexibility to evolve as future needs emerge. Raytheon Company is responsible for developing OCX, which is scheduled to enter operation in 2018.

Solving difficult technical challenges

Because GPS is so broadly used, a system crash would cause serious financial, societal and national security issues. As such, it's become a potential target for cyber attack. To protect the system from hackers, Raytheon is integrating robust cyber protections into OCX, securing the system from end-to-end against malicious cyber criminals.

OCX is also being designed to operate both GPS II and GPS III satellites concurrently, which ensures uninterrupted operations during upgrades or transitions from existing to new satellites.

In addition, Raytheon is evolving the OCX architecture to support the Launch and Checkout System (LCS) in preparation for the first GPS III satellite launch. LCS represents a significant risk reduction for the remainder of the OCX program by accelerating critical cyber security protections and validating system performance through operational tests.

Five Benefits of GPS OCX

1. Dramatic Performance Improvement

The effectiveness of the GPS system and its signals are measured in three ways:

  • Accuracy — The accuracy of GPS time and location information is essential for a wide range of applications, including navigation, cell phone service, military targeting, etc.
  • Availability — The GPS system must be available and trustworthy at all times, anywhere in the world.
  • Integrity — Users of the GPS system, whether military, civilian or commercial, must have complete confidence that the GPS signal has not been compromised in any way.

OCX will improve and enhance all three performance areas. End users will enjoy twice the accuracy of the current system, and because OCX lifts the limit on the number of satellites in the GPS constellation, signal strength will be much stronger in hard-to-reach areas like dense city streets and mountainous terrain.

To make sure those signals are secure and trustworthy, OCX is integrating the same algorithms used in the FAA's Wide Area Augmentation System and employing digital signatures on all critical external interfaces. These technologies will give GPS users an unprecedented level of system integrity.

2. Unparalleled Cyber Protection

To protect GPS from cyber threats that could compromise or interrupt the system, OCX is implementing DODI 8500.2 "Defense in Depth" information assurance standards, coupled with a wide range of proprietary cybersecurity technologies and techniques designed to harden its cyber defenses while complying with the US military and government cyber standards. In short, GPS OCX is designed to be the most secure ground system, ever.

3. Secure Information Sharing

The "internet of things" depends on fast, secure, automated information sharing. In the past, key information like clock and satellite position corrections were only available through rigid, point-to-point interfaces, and only to a very small number of users. GPS OCX will introduce a single, net-centric interface that employs state-of-the-art encryption technologies, enabling secure sharing of that information quickly and accurately, with a larger user group, when and where it's needed.

4. Modern Civil and Military Signal Compatibility

The current GPS ground control system wasn't designed to process the newest types of navigation signals. As such, offline tools are enabling current satellites to broadcast modern civil signals. The new M-code military signal, which is more accurate and jam/spoof resistant than existing signals, isn't supported by the current system at all. OCX will offer full backward and forward compatibility with all existing civil and military signals.

OCX will also introduce L1C signal compatibility with navigation systems deployed by Russia, Europe, China, Japan and India, giving users access to a much larger, more accurate network of satellites and improving coverage worldwide.

5. A Flexible, Open Architecture Built for the Future

Unlike previous generations of GPS ground systems, which were built on proprietary, closed architectures, the new GPS OCX ground system represents a departure from the past by embracing open systems. A service-oriented architecture, modular sub-systems, and the ability to easily integrate new capabilities and signals as they become available will eliminate the need to re-architect the system as its mission evolves. This approach gives OCX significant flexibility to meet future needs, and extends the life expectancy of the system.

Published On: 04/13/2015
Last Updated: 12/11/2017