How to protect against jamming and its effects

Various types of signals are used to jam GNSS signals, including pulse, continuous, wideband, or narrowband interference. The structure, type, and power of these jamming signals depend on the jammer employed. Simple generators can produce interference on a single frequency (e.g., L1) of a single satellite constellation (e.g., Global Positioning System). More complex devices can interfere with signals from several constellations (e.g., GPS, Galileo, GLONASS, BeiDou) across multiple frequencies (e.g., L1, L2, L5, E1, E5). Another factor is the structure of the jamming signal itself and how it changes during the jamming event (e.g., a simple chirp signal, a pulse signal, or “smart jamming”).

Unlike natural signal changes caused by tropospheric delays, multipath propagation, scintillations, solar storms, and cosmic radiation, jamming is a deliberate form of signal interference. It blocks GNSS signals by generating signals of usually higher power within their frequency band. This causes the end-user’s receiver to process the interference signal instead of the useful GNSS signal. As a harmful activity that hinders or prevents the use of GNSS and GNSS-based services, jamming is illegal and prosecuted by law in Poland and other countries. From a user’s perspective, jamming causes total or partial unavailability of GNSS services, preventing precise navigation, creating problems with the synchronization of power and telecommunications networks, and disrupting emergency services and crisis management coordination systems.

Press reports indicate a significant increase in jamming incidents in north-eastern Poland (especially in the Gdańsk Bay area), Lithuania, Latvia, Estonia, Finland, Sweden, Ukraine, and countries in the Mediterranean and Middle East regions. The impact of jamming can have serious consequences for the economy, industry, social life, and the daily functioning of individuals.