A regional aviation-safety team mapped GNSS interference from open ADS-B data.

The team supports civil aviation safety for a European region with several busy airports and a long stretch of coastline. Its job is to spot hazards early, inform airlines and air navigation service providers, and feed the regional safety picture. EASA has reported a notable increase in GNSS jamming and spoofing since February 2022, particularly around conflict zones and other sensitive areas, and the region had started to see it too (see references).

The evidence arrived slowly and unevenly. Crews filed reports after landing, some airlines shared them quickly and others did not, and the team had no consistent way to tell whether three reports on Tuesday were a single faulty receiver or a whole sector of degraded positioning. Building a picture for one event took about three days of analyst time.

The data to do better already existed. Aircraft equipped with ADS-B broadcast their position along with quality indicators: the navigation accuracy category (NACp) estimates position uncertainty, and the navigation integrity category (NIC) gives a containment radius. When either drops to zero, the position uncertainty is far higher than typical GNSS performance, which suggests significant interference (see references). The team had its own ground receivers and access to an open, crowdsourced ADS-B network, but no way to turn millions of messages into a map someone could act on.

Kimo Bridge was installed next to the team’s receiver archive, a Postgres database fed by its ground stations. Kimo queries the archive through the bridge and receives only aggregates, so raw tracks never leave the team’s servers. Open ADS-B data and a base map of sectors and airports were connected alongside it.

The model aggregates position reports into a fixed grid and, for each cell and hour, computes the share of distinct aircraft reporting degraded NIC or NACp. A cell is flagged only when several aircraft from different operators are affected at the same time, which filters out single-avionics faults. Each flag shows the evidence: aircraft count, the distribution of accuracy values, altitude bands and the trend over the previous 24 hours.

The output is deliberately civil and descriptive. Analysts see where positioning was degraded, when and for how many aircraft; they do not attempt to locate or characterize emitters, which is a matter for the competent authorities. A templated safety notice is drafted from each confirmed event and reviewed by a duty analyst before it goes to airlines and service providers.