Overview of the Sherlock platform

Sherlock is the EUROCONTROL central platform for monitoring and analysing the performance of Communication, Navigation and Surveillance (CNS) systems across the European ATM network.

It serves as the European network’s CNS knowledge and analytics centre, providing high quality performance information, real time monitoring, historical analysis and in depth insights into CNS behaviour. Built on a cloud based big data architecture, Sherlock brings together advanced analytics applications and inspector tools, allowing users to understand CNS performance at flight, regional and network levels.

Sherlock supports operational, technical and safety stakeholders understand emerging CNS issues and assess their potential impact on safety, capacity and network predictability.

The European CNS environment is increasingly affected by GNSS Radio Frequency Interference (RFI) and surveillance spectrum congestion.

GNSS jamming and spoofing, once rare and localised, are now observed frequently across Europe and neighbouring regions. GNSS degradation impacts multiple systems at once, leading to unreliable ADS B position reporting, degraded CPDLC operations and false cockpit safety alerts such as EGPWS or TAWS, which increase pilot workload and reduce operational predictability.

At the same time, the dense concentration of aircraft and surveillance sensors in busy airspace places growing pressure on the 1030/1090 MHz frequency band. Transponder over interrogation and spectrum congestion can degrade transponder performance, reduce the reliability of surveillance data and increase technical loads on aircraft systems. Together, GNSS interference and surveillance congestion create systemic stress on CNS infrastructure, reinforcing the need for coordinated monitoring, early detection and shared situational awareness across the European network.

As the central hub for CNS intelligence, Sherlock integrates several specialised applications into a single environment for analysing and understanding CNS behaviour across the European network.

Scope of Sherlock services

Sherlock applications provide domain-specific services and analyses:

GRID (GNSS Radio Frequency Interference Detector) provides real time detection and visualisation of GNSS jamming and - soon - spoofing. It identifies interference hotspots, analyses operational impact and supports coordinated mitigation across ANSPs, operators and authorities.

EMIT (European Monitoring of Interrogators and Transponders) monitors the 1030/1090 MHz surveillance environment, tracking interrogator activity and transponder responses to detect over interrogation, spectrum congestion and related performance issues. It helps identify hotspots in time and space, supports trend analysis and compliance monitoring, and enables coordinated mitigation across stakeholders to protect surveillance robustness.

CNS CAP (CNS Capabilities), the successor to the CNS Dashboard, offers a modern, structured overview of CNS capabilities declared by aircraft operators in flight plans, supporting planning activities, reporting and capability assessments.

SSI (Surveillance System Infrastructure) is a centralised database of surveillance assets, providing visibility of coverage and capabilities to support planning, optimisation and infrastructure management.

RMA HMU (Regional Monitoring Agency / Height Monitoring Unit) supports RVSM compliance monitoring through continuous height keeping performance analysis, in line with the European RMA framework.

ACAS analytics within Sherlock enable the analysis of ACAS behaviour and Resolution Advisory events, helping to identify operational drivers and support safety improvements.

A public presentation of the Sherlock platform, its mission and positioning is available here, https://www.eurocontrol.int/tool/sherlock on the EUROCONTROL website.

GRID (GNSS Radio Frequency Interference Detector)

GRID (GNSS Radio Frequency Interference Detector) is Sherlock’s dedicated capability for detecting, analysing and visualising GNSS jamming and spoofing, across the European aviation network. It provides a consistent, data driven view of how GNSS interference affects aircraft operations, enabling both rapid situational awareness and deeper performance investigations.

Built on real time surveillance and navigation data, GRID identifies when and where aircraft experience abnormal GNSS behaviour.

The platform characterises interference events based on intensity, duration, altitude and geographical spread, allowing users to distinguish between local, short term disturbances and large scale, sustained RFI events.

GRID offers pan European visualisation through an interactive map that highlights interference hotspots and emerging trends.

Users can follow event evolution in time, view affected flight trajectories and analyse the vertical and horizontal extent of the disturbance.

Historical replay functions allow reconstruction and comparison of past events, supporting root cause investigations and long-term pattern analysis.

GRID also provides insights into the operational impact of GNSS degradation by showing how an interference event affects surveillance continuity (e.g. ADS B outages), navigation accuracy and flight behaviour. By correlating RFI effects with flight trajectories and CNS performance indicators, it supports both technical assessments and operational decision making.

As part of the Sherlock platform, GRID seamlessly links with the Flight and Traffic Inspectors, enabling users to zoom from a wide area spectral disturbance down to individual flight impacts. This integration supports coordinated mitigation, improves stakeholder situational awareness and enhances the overall resilience of European CNS services.

Access conditions

Access to Sherlock is granted to operational stakeholders with a validated need for CNS performance information, including ANSPs, regulators, aircraft operators and safety authorities. Access requires authentication with a dedicated set of EUROCONTROL credentials, role‑based permissions and acceptance of relevant data‑use and confidentiality policies. For more information you can contact us at sherlock@eurocontrol.int

Direct link to Sherlock platform: https://sherlock.eurocontrol.int/home