Mounted Positioning, Navigation, and Timing Device to make GPS more Reliable

GPS Technology has been used to provide Soldiers in the field with position, navigation and timing information. However the signal's susceptibility to interference has been a major problem for the military. In addition, each platform function, such as driver navigation, overall situational awareness or weapons targeting information requires a separate GPS receiver, creating additional size, weight and power issues inside the vehicle.

To address these concerns, the Army's Communications-Electronics Research, Development and Engineering Center (CERDEC) has developed the Mounted PNT system. The mounted PNT device (Position, Navigation, and Timing), currently under development is a scalable and upgradable PNT system for mounting within a platform (ground vehicle, aircraft, etc.). The mounted device will fuse GPS with alternate navigation and timing technology to provide assured PNT to client platforms and systems. This mounted device will distribute PNT data to multiple systems directly and via network (VICTORY) on a platform replacing the need for multiple GPS devices on a single platform.

GPS signal issues occur in a variety of environments, including city buildings, forests and mountainous terrain, or from adversarial sources who employ jamming devices to degrade or completely block the signal. To aid GPS, they grouped an array of sensors based on their function and the platform's mission to form the Mounted PNT system.

Sensor options include inertials, which use accelerometers and gyroscopes to measure position orientation and velocity; radios to conduct RF ranging, which obtains distances by measuring the time it takes the signal to go from Point A to Point B; cameras to shoot and compare pictures frame by frame to determine movement, and the Chip Scale Atomic Clock, which provides very accurate time. No single PNT sensor will provide you with all the required information. Each one will have its own specific strength and weakness, but when these are integrated to form a single system they can all work together to provide an overall boost in performance.

The system is adaptable and can be tailored prior to fielding to reflect mission requirements. For example, developers can replace just the GPS module or individual sensors rather than having to replace the entire system. The flexible design will also seamlessly operate with the new Military Code, or M-Code, signal, which will replace the current GPS signal to help provide protection against intentional GPS interference and is a component of the Army's GPS modernization effort.

CERDEC has been developing PNT capabilities since the 1960s and currently Direct Reporting Program Manager PNT, which is providing Assured PNT to mounted and dismounted Soldiers. The US Army has deemed Assured PNT as a critical function for mission success and Soldier safet.

CERDEC has already shown success in addressing future Mounted PNT capabilities by developing a prototype system that consolidates multiple warfighting function systems into one mounted product. This effort known as Hardware/Software Convergence features one chassis that contains separate payload cards to address areas such as PNT, communications, electronic warfare and mission command.

By using a chassis, the platform could alleviate space-stealing components such as transit cases, power supplies, mounts, and cabling. It will provide an entire PNT solution as well as a system clock that provides slot to slot synchronization to less than 80 pico seconds, or less than 80 trillionths of a second.

The system will feature an open architecture and open standards design, which will provide a competitive field to develop hardware and software updates instead of entire system builds, Howe said.