icohangar-ops/geopulse

GNSS ground-station anomaly detection for disaster early warning in Africa — 5-algorithm engine on ScyllaDB # GeoPulse — GNSS Ground Station Anomaly Detection **Real-time GNSS position monitoring and anomaly detection for disaster early warning in Africa.** Built for the SATNAV G4D-RR Hackathon — EU-funded GNSS for Disaster Risk Reduction & Early Warning Systems. ## Overview GeoPulse ingests continuous GNSS position streams from a network of 24 ground stations across Africa, stores time-series geospatial data in ScyllaDB, and runs real-time anomaly detection to flag precursor signals for earthquakes, landslides, and volcanic activity. ### Architecture ``` ┌─────────────┐ SSE ┌──────────────┐ ┌───────────────┐ │ Dashboard │◄────────────│ Next.js API │────►│ ScyllaDB │ │ (React 19) │ │ /api/stream │ │ gnss_readings│ │ Leaflet Map │ │ Simulator │ │ anomalies │ │ Recharts │ │ Detection │ │ hourly_stats │ └─────────────┘ └──────────────┘ └───────────────┘ │ ▼ ┌───────────┐ │ SQLite │ │ (Stations,│ │ Alerts) │ └───────────┘ ``` ## Features ### Real-Time Monitoring - **24 GNSS stations** across 7 African tectonic risk zones - **Live data streaming** via Server-Sent Events (300ms per station cycle) - **Interactive map** with health-colored markers (green/amber/red) - **Time-series charts** — 3D position residual + N/E/U component decomposition - **Station health popups** with PDOP, satellite count, and 3D residual ### Anomaly Detection Engine (5 Algorithms) | Algorithm | Method | Warning | Critical | |-----------|--------|---------|----------| | Position Drift | Running z-score on 3D residual | >3σ | >4σ | | Velocity Spike | Absolute 3D velocity threshold | >0.5 mm/s | >2.0 mm/s | | Signal Degradation | Satellite count + PDOP | 6 | 10 | | Multipath Detection | Oscillation rate + PDOP correlation | >60% oscillation + PDOP>4 | — | | Elevation Jump | Sudden vertical displacement | >15mm | >20mm | ### Risk Zones Monitored - **East African Rift** — Active dive …