GNSS Interference Map

About SAT-JAM

SAT-JAM is a real-time monitoring system for detecting GNSS (Global Navigation Satellite System) signal jamming across Europe. The system analyzes satellite-based observations to identify interference patterns and quantify their spatial and temporal extent.

The Map

The interference map displays the fraction of observations affected by jamming at each location over a 30-day rolling window. Each hexagonal cell represents a geographic area, with colors indicating the severity of jamming:

• Green (0.0-0.2): Minimal jamming - safe operations
• Yellow (0.2-0.4): Low interference - monitor
• Orange (0.4-0.6): Medium interference - caution advised
• Red (0.6-0.8): High interference - risky operations
• Dark Red (0.8-1.0): Critical jamming - avoid critical operations

Data Sources

All data is sourced from the Copernicus Data Space Ecosystem, which provides free and open access to satellite data. Specifically, we use:

• GNSS Observations: Raw receiver independent exchange format (RINEX) observations from Sentinel satellites
• Precise Orbits: Extended Orbit File (EOF) format precise satellite position data

Data Processing

The processing pipeline follows these steps:

1. Data Acquisition: GNSS observations and EOF position data are downloaded nightly from Copernicus
2. Coordinate Matching: Observation timestamps are matched with interpolated satellite positions using linear interpolation
3. Coordinate Conversion: Satellite positions are converted from ECEF (Earth-Centered, Earth-Fixed) coordinates to geographic latitude/longitude
4. Anomaly Detection: Signal strength anomalies are identified using z-score statistics (values < -3σ indicate jamming)
5. Spatial Aggregation: Data is binned into hexagonal cells using H3 geospatial indexing at resolution 2
6. Temporal Aggregation: Results are accumulated over a 30-day rolling window for stability
7. JSON Export: Processed data is exported to JSON format for web visualization

About the Author

Kian Bostani Nezhad is a PhD student at the Technical University of Denmark (DTU) in 2026. This project was developed as part of research into GNSS signal integrity and resilience monitoring.

Technical Implementation

The website uses modern web technologies including:

• Frontend: Leaflet.js for interactive mapping, H3.js for hexagonal binning
• Backend: Python for data processing with georinex, scipy, and h3-py libraries
• Data Processing: Nightly automated pipeline scheduled via cron

Contact & Attribution

For questions or collaboration inquiries, please contact the author. Data is provided by the Copernicus Program, funded by the European Union.