GPS interference levels reported by aircraft transponders, aggregated into geographic zones across the Baltic region. Data comes from GPSJam.org which collects ADS-B Navigation Accuracy Category (NACp) values.
Data source
GPSJam.org — GPS interference heatmap from ADS-B NACp degradation
Collection frequency: every 72 hours (upstream update cadence)
For each geographic zone (Estonia, Latvia, Lithuania, Kaliningrad, Finland-S, etc.):
Total aircraft reporting position in the zone
Degraded aircraft — those with NACp below the expected threshold
Interference rate — percentage of degraded aircraft
Severity — HIGH (>10%), MEDIUM (5–10%), LOW (<5%)
Interpretation
Persistent GPS interference near Kaliningrad (typically 20–35%) is attributed to Russian military jamming systems. Elevated rates in Estonia, Latvia, or Finland indicate spillover or deliberate targeting of civilian navigation.
Limitations
Snapshots update approximately every 72 hours — not real-time
NACp degradation can have non-jamming causes (ionospheric activity, equipment issues)
Coverage depends on ADS-B receiver density in each zone