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Image: MaritimeTraffic.com What’s new: The UK Maritime and Coast Guard Agency advising shipping about operations without GPS/GNSS. Why it’s important: GPS jamming and spoofing has resulted in groundings, collisions, fires, and ships being seized for sailing in territorial waters. As an island nation, the UK has an especially keen interest in the safety and efficiency of maritime commerce. UK waters are busy and congested. The United Kingdom has been a maritime world leader for centuries. What else to know: The UK’s Royal Institute of Navigation (RIN) issued a report on GNSS interference in maritime earlier this year. It has an on-going education program and is assisting the UK government for navigation issues. – Well done RIN! The notice includes the following forward-looking bit. We think every nation and every navigator should be looking forward wrt GNSS denied. “MCA continues to engage with IMO member states to establish the standards and […]
Analysis Summary
# Best Practices: Operating in GNSS-Denied and Degraded Environments
## Overview
These practices address the critical vulnerabilities associated with Global Navigation Satellite Systems (GNSS) such as GPS, Galileo, GLONASS, and BeiDou. They provide a framework for maintaining maritime safety and operational continuity in the face of signal jamming (blocking), spoofing (false data), and environmental degradation.
## Key Recommendations
### Immediate Actions
1. **Conduct a Dependency Audit:** Identify all shipboard and shore-based systems relying on GNSS (e.g., ECDIS, AIS, Radar, DP systems, and NTP/PTP timing networks).
2. **Verify Conventional Proficiencies:** Ensure bridge officers and navigators are immediately capable of performing manual position fixing (visual/radar) and dead reckoning.
3. **Cross-Check Navigation Inputs:** Regularly compare GNSS-derived positions against independent sources (Radar ranges, visual bearings, depth contours) to detect spoofing.
4. **Issue Standing Orders:** Mandate immediate reporting of PNT (Position, Navigation, and Timing) anomalies to Vessel Traffic Services (VTS) and relevant authorities.
### Short-term Improvements (1-3 months)
1. **Update Risk Assessments:** Formally integrate PNT degradation scenarios into the Safety Management System (SMS) and port operational risk registers.
2. **Enhance Training Programs:** Implement drills specifically focused on "GNSS-Denied" scenarios, emphasizing the transition from automated to manual navigation.
3. **Review Timing Dependencies:** Identify critical IT and communication infrastructure that uses GNSS for UTC traceability and implement local oscillators or holdover clocks where possible.
### Long-term Strategy (3+ months)
1. **Diversify PNT Sources:** Invest in and install "Failure Mode Diverse" technologies such as eLORAN, Inertial Navigation Systems (INS), or VDES R-Mode.
2. **Infrastructure Hardening:** Upgrade to multi-constellation, multi-frequency (MCMF) receivers and consider Anti-Jam Antennas (AJAS).
3. **Automated Alternatives:** Explore the adoption of automatic visual fixing, automatic celestial fixing, and 5G-based positioning as these technologies mature.
## Implementation Guidance
### For Small Organizations (Fishing vessels, small operators)
- **Manual Proficiency:** Focus heavily on traditional seamanship; maintain paper chart backups or independent battery-powered handheld navigation tools.
- **Awareness:** Train crew to recognize "GPS jump" or erratic AIS behavior as a sign of interference.
### For Medium Organizations (Short-sea shipping, regional ports)
- **Standardized Procedures:** Create checklists for "Loss of GNSS" to ensure consistent response across a fleet.
- **Local Resilience:** Ensure port management systems have manual override capabilities for logistics and vessel tracking.
### For Large Enterprises (Global carriers, major energy hubs)
- **System Integration:** Deploy Integrated Bridge Systems (IBS) that can automatically fuse data from non-satellite sensors (Inertial + Doppler Log + Radar).
- **Policy Advocacy:** Engage with IMO and national regulators to support the proliferation of international PNT standards.
## Configuration Examples
*While specific code is not provided in the guidance, the following configuration logic is recommended:*
- **NTP/PTP Synchronization:** Configure network timing servers to prefer a local atomic clock or high-stability oscillator as a secondary stratum if the GNSS primary source exceeds a specific jitter/offset threshold.
- **ECDIS Alarms:** Set "Difference of Position" alarms to trigger if the GNSS position deviates significantly from the Dead Reckoned (DR) or Radar-estimated position.
## Compliance Alignment
- **IMO Standards:** Alignment with International Maritime Organization standards for PNT and bridge equipment.
- **UK MCA MGN 719 (M+F):** Direct compliance with the Maritime and Coastguard Agency's guidance on GNSS-denied operations.
- **NIST Cybersecurity Framework:** Relates to "Protect" and "Detect" functions regarding signal integrity.
## Common Pitfalls to Avoid
- **Over-reliance on AIS:** Remembering that AIS is GNSS-dependent; if your GPS is spoofed, your AIS is likely broadcasting false data to others.
- **Ignoring the "Timing" in PNT:** Failing to realize that communication networks and digital logs may fail if GNSS-derived timing (UTC) is lost, even if the vessel is stationary.
- **"Alarm Fatigue":** Disabling GNSS-related alarms during localized interference instead of switching to a verified alternative sensor.
## Resources
- **UK Maritime and Coastguard Agency (MCA):** [www.gov.uk/mca]
- **Royal Institute of Navigation (RIN):** [rntfnd[.]org/category/blog/]
- **Resilient Navigation and Timing Foundation:** [rntfnd[.]org]
- **US Congress/Legislative Advocacy:** [congress[.]gov]