Full Report
Image: Shutterstock What’s new: An opinion piece in Aviation Week about using eLoran as resilient PNT for aviation. Why it’s important: Aviation seems to be the industry most impacted by jamming and spoofing at the moment, especially unmanned aviation. We have heard reliable reports that both Ukraine and Russia are using eLoran for timing and some drones. What else to know: As is mentioned in the article, before the advent of GPS, ICAO listed Loran as an aviation system in Annex 10. In fact, in the 1970’s the FAA funded construction of additional Loran transmitter sites in the interior of the U.S. to enable general aviation to use it from coast to coast. Dr. Okuary Osechas is a researcher at the Zurich University of Applied Sciences (ZHAW) and chairs two EUROCAE standardization groups, including Performance Based Navigation. Opinion: An Expeditious Solution To GPS Interference: Restoring eLoran To Aviation Okuary […]
Analysis Summary
# Best Practices: Resilient PNT (Positioning, Navigation, and Timing) for Aviation
## Overview
These practices address the growing threat of Global Navigation Satellite System (GNSS) interference, specifically **jamming and spoofing**. As GPS becomes increasingly vulnerable to electronic warfare and malicious actors, aviation stakeholders must adopt eLoran (enhanced Loran) and other terrestrial-based systems to ensure operational continuity and safety.
## Key Recommendations
### Immediate Actions
1. **Assess GNSS Dependency:** Audit all unmanned and manned flight operations to identify systems that rely solely on GPS for navigation or timing.
2. **Deploy Spoofing Awareness Training:** Educate pilots and operators on identifying the signs of GPS interference (e.g., erratic altitude readings, map drifts, or "invalid position" alerts).
3. **Implement Pilot-in-the-Loop Reporting:** Establish a standardized protocol for reporting PNT anomalies to Air Traffic Control (ATC) or relevant regulatory bodies immediately upon detection.
### Short-term Improvements (1-3 months)
1. **Integrate Multi-Sensor Fusion:** Begin software updates to drone flight controllers and avionics to incorporate non-GNSS inputs (Inertial Measurement Units, barometers, and visual odometry).
2. **eLoran Receiver Evaluation:** Test eLoran-capable receivers for timing synchronization in ground stations and critical infrastructure to mitigate "GPS-denied" scenarios.
3. **Risk Modeling:** Conduct impact assessments on how GNSS degradation affects Beyond Visual Line of Sight (BVLOS) decision-making and Unmanned Aircraft System Traffic Management (UTM).
### Long-term Strategy (3+ months)
1. **Advocate for Infrastructure Restoration:** Engage with national aviation authorities (FAA/EASA) to restore and modernize eLoran transmitter sites as a sovereign terrestrial backup.
2. **Standardization Alignment:** Adopt standards developed by **EUROCAE** regarding Performance-Based Navigation (PBN) that include resilient PNT requirements.
3. **Diverse PNT Architecture:** Move toward a "PNT Ecosystem" that combines LEO (Low Earth Orbit) PNT, terrestrial eLoran, and traditional GNSS to eliminate single points of failure.
## Implementation Guidance
### For Small Organizations (e.g., Drone Operators)
- **Redundancy:** Ensure all drones have "Return to Home" functions configured to use non-GPS sensors (like optical flow) if GNSS signal is lost.
- **Firmware Updates:** Regularly patch GPS receivers to include latest anti-spoofing software filters.
### For Medium Organizations (e.g., Regional Carriers, UTM Providers)
- **Hardware Upgrades:** Invest in antennas with CRPA (Controlled Reception Pattern Antenna) technology to nullify jamming signals.
- **Policy Development:** Create SOPs (Standard Operating Procedures) for operations in high-risk electronic warfare zones (e.g., Eastern Europe or sensitive borders).
### For Large Enterprises (e.g., National Airlines, Infrastructure Managers)
- **Lobbying & Advocacy:** Use "Resilient PNT Key Talking Points" to influence government funding for terrestrial PNT backups.
- **Systemic Resilience:** Integrate eLoran timing into corporate data centers and communications networks to prevent synchronization failures if GPS is jammed.
## Configuration Examples
*While specific code is not provided in the article, the following configuration approach is recommended:*
* **System Preference Mapping:** Configure PNT suites to prioritize GNSS but automatically failover to eLoran/INS if the "Protection Level" (PL) exceeds the "Alert Limit" (AL).
* **ICAO Annex 10 Compliance:** Ensure all backup navigation systems are configured to meet the legacy standards formerly used for Loran systems in aviation.
## Compliance Alignment
- **ICAO Annex 10:** Aeronautical Telecommunications standards.
- **EUROCAE PBN Standards:** Guidelines for Performance-Based Navigation.
- **NIST PNT Profile:** Leveraging the NIST Cybersecurity Framework to improve PNT resilience.
## Common Pitfalls to Avoid
- **The "GPS Genius" Trap:** Assuming that because GPS is highly accurate, it does not require a backup.
- **Timing Overlook:** Forgetting that GPS is a timing source. If timing fails, communication networks and UTM systems often fail shortly after.
- **Single-Source Dependency:** Relying solely on LEO PNT or GNSS without a terrestrial-based alternative like eLoran.
## Resources
- **Resilient Navigation and Timing Foundation:** [rntfnd[.]org]
- **US Lawmaker Outreach:** [congress[.]gov]
- **Talking Points & Templates:** [rntfnd[.]org/resilient-pnt-key-talking-points/]
- **Standardization Bodies:** [eurocae[.]net]