A-PNT: Positioning When GNSS Cannot Be Trusted
Jamming overwhelms or blocks GNSS signals, causing position data to become unavailable or unreliable. Spoofing is more deceptive: false signals can make systems display a plausible but incorrect position without an obvious loss of service. A-PNT provides an independent, proven source of position and timing, helping operators maintain trusted information in both scenarios.
GNSS Disruption is a Vessel-Wide Operational Risk
Compromised Position Data
Jamming can make GNSS position unavailable, while spoofing can make systems display a plausible but incorrect vessel position.
Loss of Fleet Visibility
Shore teams may struggle to distinguish genuine vessel movement from position data affected by jamming or spoofing.
Unreliable Records
Incorrect position data can distort vessel tracks, voyage histories and the records available for later incident review.
Difficult Recovery
Crews may need to verify affected systems and position data before they can safely return to normal operations.
Why GNSS Protection Alone May Not Be Enough
Many resilience measures are designed to protect, strengthen or validate GNSS reception. They can improve performance in some conditions, but they still depend on GNSS and may be challenged when signals are heavily jammed or convincingly spoofed.
A-PNT takes a different approach. It provides an independent position source that can be compared with GNSS-derived information, helping operators identify when that information can no longer be trusted.
The key difference is independence: A-PNT doesn’t try to repair the affected GNSS signal. It provides a separate position reference.
How Assured Positioning Works
RockFLEET Assured receives both the vessel’s conventional GNSS-derived position and an independent position based on Iridium PNT. It continuously compares the two sources to determine whether the GNSS information can still be trusted.
When the positions remain aligned, normal reporting continues. If they begin to diverge, or GNSS becomes unavailable, the system can generate alerts, retain an event log and continue reporting the independently derived position.
This information can be presented onboard through a bridge display, monitored across a fleet in Cloudloop Tracking, or delivered into an existing vessel management platform.
The result is a clear integrity status for the vessel’s position, available to both onboard and shore-side teams.
Why Choose Iridium PNT?
Signals up to 1,000 times stronger than GNSS
Low Earth Orbit architecture
Different spectrum from GNSS
Authenticated PNT source
Worldwide operational coverage
How Maritime Teams Use Assured Positioning
GNSS spoofing and jamming can leave crews navigating on incorrect information without knowing it. RockFLEET Assured helps bridge teams identify integrity issues early, providing access to an independent position reference.
From the Bridge
- Know immediately when GNSS may be spoofed or jammed
- See an independent position reference alongside existing navigation systems
- Continue operating with confidence when positioning data is in question
- Avoid introducing new systems and workflows on the bridge.
A GNSS disruption affecting one vessel is a navigation issue. A disruption affecting multiple vessels becomes an operational risk. RockFLEET Assured helps shore teams maintain visibility when conventional positioning systems are under pressure.
Provides Remote Oversight
- Monitor vessel position integrity remotely
- Identify vessels affected by GNSS disruption
- Receive alerts before issues escalate
- Maintain awareness through high risk operating regions.
When navigation integrity is questioned, organizations need more than assumptions. They need evidence. RockFLEET Assured helps create an independent record of positioning and integrity events to support investigation, compliance and reporting.
Providing an Evidence Trail
- A trusted position of record
- Evidence when GNSS disruption occurs
- Support for investigations and reporting
- Greater awareness of navigation risk exposure.
Adding GNSS resilience can be expedited quickly with no vessel modifications. RockFLEET Assured is designed to fit into existing vessel environments, helping technical teams deploy assured positioning with minimal operational impact.
Integration Flexibility
- Straightforward vessel deployment
- Compatibility with existing systems
- Flexible integration pilot options
- Remote management and support
GNSS disruption can affect navigation, vessel tracking, operational decision making, and commercial exposure. RockFLEET Assured helps organizations improve resilience before a disruption becomes an operational incident.
Responding to Identifiable Risk
- Protect vessel operations
- Reduce liability exposure
- Improve awareness of navigation risk
- Support business continuity during disruption events
For Commercial Vessels
RockFLEET Assured delivers Iridium PNT-based A-PNT in a compact, above-deck dome terminal, providing an authenticated position source for trusted vessel position reporting in GNSS-challenged environments. Optional bridge chart view shows assured position alongside GNSS position / track.
Marine-grade and simple to install, RockFLEET Assured requires no below-deck electronics unless you choose the optional bridge view. Configuration is managed OTA, with commissioning via a Bluetooth LE app, plus APIs for integrating vessel location and events.
For Embedded and Autonomous Systems
For integrators building assured positioning into their own systems, the RockBLOCK APNT evaluation kit provides Iridium PNT-based A-PNT in a compact module with standard interfaces, ideal for land vehicles, UAVs, autonomous systems and remote assets operating in GNSS-challenged environments.
RockBLOCK APNT is designed for customers testing APNT performance, integration, and resilience in challenging environments. Antenna placement, cable length, environment, and asset speed can all affect performance.
Two Operational Views. One Trusted Position Source.
RockFLEET Assured gives both ship and shore teams a practical way to work when GNSS can’t be trusted.
On board, the bridge view helps crews compare GNSS with an independent position reference, spot anomalies quickly, and respond with more confidence. Ashore, Cloudloop Tracking helps operators maintain fleet visibility, monitor integrity alerts, and keep oversight when disruption affects one vessel or many
Bridge view
- Compare GNSS with an independent reference
- Spot anomalies quickly
- Support confident onboard decisions
Cloudloop Tracking
- Monitor vessel position integrity remotely
- Identify affected vessels earlier
- Maintain fleet visibility through disruption
Built on 23 Years of Trusted Tracking Experience
Ground Control has spent 23 years delivering reliable satellite tracking and messaging solutions for critical operations, including through our sister company, YB Tracking. Our Assured Positioning, Navigation and Timing (A-PNT) solutions build on that heritage for GNSS-disrupted maritime environments, backed by Ground Control’s experience as an Iridium gold tier partner since 2005.
Stay On Track in GNSS-Denied Environments
Whether you’re in commerical shipping, deploying autonomous systems, or operating in contested areas, RockFLEET Assured and RockBLOCK APNT deliver reliable, spoof-resistant timing and location when GPS can’t.
Email hello@groundcontrol.com or complete the form to discuss integration options, request pricing, or see how A-PNT fits into your application.