Field Detection of GNSS Interference Using Smartphones at Jammertest 2025

This paper presents the evaluation of the CrowdShield app, a smartphone-based solution for detecting Global Navigation Satellite System (GNSS) interference, tested during Jammertest 2025—a large-scale, controlled event in Norway for assessing resilientnavigation technologies. The app leverages Automatic Gain Control (AGC) measurements provided by the Android GNSS API (Application Programming Interface) from dual-frequency smartphones to identify interference in L1/E1 and L5/E5a bands. A variety of open-sky interference tests were performed during Jammertest, including static, dynamic (motorcade), and airborne scenarios to validate the app performance and detection capabilities in realistic conditions. Static tests near Bleik demonstrated the app’s ability to detect a variety of jamming/meaconing signals, with AGC values showing distinct trends varying with interference power levels. Dynamic motorcade tests, involving driving nearby a test vehicle equipped with low-power jammers, confirmed the app’s sensitivity in mobile environments. Airborne tests, conducted in collaboration with Eurocontrol on a test aircraft, showed that AGC measurements provided additional insights compared to ADS-B Navigation Integrity Category (NIC) values in presence of a jammer located in Andøya airport, underscoring AGC’s potential as a complementary detection tool. The study emphasizes the value and potential of crowdsourced smartphone data for mapping interference spatially and temporally, supporting robust detection strategies that can facilitate interference mitigation. This research demonstrates the viability of mass-market devices to detect vulnerabilities in critical GNSS signals, advancing the use of accessible technology for resilient navigation systems.

TEGEDOR Javier;  PICCOLO Andrea;  GIOIA Ciro;  BARBERO Marco; 

2026-02-27

Institute of Navigation

JRC144749

978-0-936406-43-5 (online),   

2330-3646 (online),   

https://www.ion.org/publications/abstract.cfm?articleID=20523,    https://publications.jrc.ec.europa.eu/repository/handle/JRC144749,   

10.33012/2026.20523 (online),