Armed forces’ reliance on Global Navigation Satellite System (GNSS) is ubiquitous, depending on positioning, navigation and timing (PNT) data for everything from navigation and positioning of ground vehicles and dismounted ground forces to weapon guidance and synchronizing elements of C4ISR (Communications, Computers, Intelligence, Surveillance, and Reconnaissance). In fact, reliance on PNT technology is embedded in all military operations. This makes the issues facing PNT challenging but crucial. The role of resilient PNT in today’s defense programs is of critical importance to security globally.
Let’s have a look at what is Positioning Navigation and Timing (PNT) all about.
As per the US Department of Transportation: PNT is a combination of three distinct, constituent capabilities:
- Positioning, the ability to accurately and precisely determine one’s location and orientation two-dimensionally (or three-dimensionally when required) referenced to a standard geodetic system (such as World Geodetic System 1984, or WGS84);
- Navigation, the ability to determine current and desired position (relative or absolute) and apply corrections to course, orientation, and speed to attain a desired position anywhere around the world, from sub-surface to surface and from surface to space; and
- Timing, the ability to acquire and maintain accurate and precise time from a standard (Coordinated Universal Time, or UTC), anywhere in the world and within user-defined timeliness parameters. Timing also includes time transfer.
When PNT is used in combination with map data and other information (weather or traffic data, for instance) the result is the most popular and recognizable service–the modern navigation system better known as the Global Positioning System (GPS). Since the development of GPS, PNT based on satellite input has become the cornerstone of critical applications in maritime, aviation, government and defense as well as commercial industry, allowing receivers to determine location to high precision (within a few meters) using time signals transmitted from space. With time and position data, navigation can be provided.
Also Read: What is GPS III & how capable it is?
Why is time important in PNT?
Determining a precise position from satellite signals depends on accurately measuring the distances between receiver and satellite, and that depends on very accurate measurement of the radio signal’s travel time from the satellite to the receiver.
What is resilient PNT and why it is important for military missions?
Resilient positioning, navigation and timing (RPNT) is the convergence of traditional positioning, navigation and timing technology with non-traditional and new emerging technology to improve the reliability, performance and safety of mission-critical applications. Resilience offers accurate and trusted time and location information by protecting, authenticating and offering alternatives to existing PNT sources such as GNSS. Traditional PNT devices utilize various alternative internal components to maintain holdover of the PNT data during loss of GNSS input, but are susceptible to drift over time, meaning the information becomes less accurate. Resilient PNT makes PNT applications resilient against GNSS signal interference, jamming and spoofing, issue alerts and provide alternative sources of navigation and positioning, and suitable for operation in GNSS-denied environments. Resilient PNT solutions can be deployed across defense in command centers and on vehicles, ships, aircraft and personnel, where a discrepancy in data accuracy, availability or stability can impact the safety, security and mission success of military operations.
Today’s military communications and information dominance systems rely on available and accurate PNT signals to provide leaders with the information required to make timely and effective decisions. Signals provided by GNSS represent the gold standard in terms of availability and accuracy. However, threats to GNSS affect numerous military defense systems, all of which rely on trusted GNSS for position, navigation and timing: C4ISR systems, signal intelligence applications, mounted navigation units, and/or sensor payloads. For all of these systems a loss of GNSS accessibility and integrity translates directly to degraded operations and can mean the difference between mission success and failure or even life and death.