GPS jamming and spoofing are now a daily reality for vessels in the Arabian Gulf, Red Sea, Eastern Mediterranean and Black Sea. When the signal is disturbed, the bridge can lose its position at the worst possible moment. To address this, Master Systems now offers PNT Guard, an Assured Position, Navigation and Timing (APNT) solution for merchant and offshore vessels.

What Are GPS Jamming and Spoofing?

Jamming blocks the satellite signal, so the receiver cannot find a position. Spoofing is different. It sends false signals, so the receiver shows a wrong position without any obvious warning. Both problems affect GNSS, the system behind GPS, GLONASS, Galileo and BeiDou.

Why Another GNSS Receiver Does Not Solve the Problem

Many operators think switching constellations will help. Unfortunately, it often does not. During strong interference, all four systems can be affected at the same time. Adding a second GNSS receiver also gives limited protection, because it depends on the same type of signal. The bridge needs a source that works in a different way.

How PNT Guard Works

PNT Guard uses encrypted and authenticated signals from the Iridium low-earth-orbit satellite network. These signals are much stronger than GNSS signals. They are also authenticated, which makes them highly resistant to jamming and spoofing.

The system compares the ship’s GNSS feed with the Iridium-based position. If the two do not match, PNT Guard raises an alert. As a result, the crew knows when GNSS data cannot be trusted.

What Is in the System

PNT Guard has two units.

Above deck unit

• Holds both a GNSS receiver and an APNT receiver
• Uses encrypted communication, over the air and over the wire
• Has an internal battery that keeps it running, even if the power cable is cut
• Accepts 7 to 32 VDC power
• Mounts flat or on a horizontal or vertical rail

Below deck unit

• 13.3 inch touchscreen display with day and night modes
• Map view showing both APNT and GNSS positions side by side
• Visual and audible alarms when spoofing or jamming is detected
• NMEA 0183 output for chart plotters, autopilots and other bridge equipment

Key Benefits

• Independent backup position. It continues to provide position, speed over ground (SOG) and course over ground (COG) with approximately 10 m accuracy when GNSS is degraded.
• Clear warnings. Operators see the difference between the two positions on screen, along with an estimated error circle for GNSS.
• Easy integration. Standard NMEA 0183 output works with existing bridge systems.
• Built for the bridge. The below deck unit is certified for bridge installation under IEC 60945 and IEC 62288.
• Data for review. The system stores 60 days of logs for analysis after an incident.

Remote Monitoring Through SkyRouter

In addition, PNT Guard works with the SkyRouter platform. Fleet managers can track vessels in real time and set up alerts using geofences and risk profiles. Data is also available in JSON format and can be streamed through WebSocket to a CMS or other situational awareness platform.

Who Should Consider PNT Guard?

PNT Guard suits operators of merchant and offshore vessels, especially those that trade in areas with frequent interference. Its purpose is to help avoid collisions, groundings, unintended entry into restricted waters and course deviations caused by false position data. If you are not sure whether it fits your fleet, the Master Systems team can discuss your routes and bridge setup with you.

Frequently Asked Questions

What is PNT Guard?
PNT Guard is an APNT solution that gives vessels an independent position source using the Iridium satellite network. It also detects GNSS jamming and spoofing.

Who offers PNT Guard?
Master Systems offers PNT Guard to merchant and offshore vessel operators. You can contact the team for product details and quotes.

How is PNT Guard different from a second GPS receiver?
A second GNSS receiver relies on the same type of signal. If interference hits all constellations, both receivers can fail. PNT Guard uses Iridium signals, so it does not depend on GNSS.

How accurate is the backup position?
PNT Guard provides position, SOG and COG with approximately 10 m accuracy when GNSS is degraded.

Can PNT Guard connect to my existing bridge equipment?
Yes. It outputs standard NMEA 0183 data, so it can feed chart plotters, autopilots and other navigation equipment.

What happens if the vessel loses power to the unit?
The above deck unit has an internal battery. It keeps the unit running and also protects against cable cutting during piracy.

Can I monitor the vessel from shore?
Yes. Through the SkyRouter platform, you can track vessels, set geofences and receive alerts.

Is PNT Guard certified?
The below deck unit is certified for bridge installation under IEC 60945 and IEC 62288. The above deck unit is IEC 60945 certified.

Get Started with Master Systems

GNSS interference is not going away soon. A reliable backup position helps your crew navigate with confidence. To learn more about PNT Guard or request a quote, contact Master Systems today.