903 KB0 KB200620252025Blatnik, Aljažštevilka:4letnik:92str. 157-165ISSN:0013-5852COBISSID_HOST:254635779URN:URN:NBN:SI:doc-WCQHQLC8slElektrotehniška zveza SlovenijeElektrotehniški vestnikGNSS receiverjammingmotenjeprenos časasatelitska navigacijasatellite navigationsprejemnik GNSStime synchronizationVrednotenje ranljivosti sprejemnikov GNSS za napade z motenjem signala|Modern technologies, spanning from sophisticated autonomous vehicles to next-generation telecommunication networks, deeply rely on satellite navigation. Precise positioning and accurate time transfer are not only vital for generating reliable navigation data but also serve as a crucial mechanism for synchronizing decentralized systems. Our increasing economic reliance on dependable Global Navigation Satellite Systems (GNSS) creates a considerable weakness, making us susceptible to malicious attacks aimed at disrupting receiver operations. While a successful attack might not be inherently dangerous if users are aware of it, the true problem arises when intentional interference subtly alters navigation data. This leads to a gradual decline in the reliability of the provided position and time information, rather than an outright system failure. Even sophisticated GNSS receivers can't fully prevent this manipulation, and such compromised data can result in significant economic losses and, in critical situations, even put lives at risk. This paper tackles a concerning fourfold (400%) surge in reported GNSS jamming incidents during the second quarter of 2024. It outlines technological countermeasures integrated into modern receivers to lessen the impact and consequences of such attacks. Furthermore, it provides recommendations for end users to enhance the resilience of GNSS-dependent systems. The article details comprehensive measurements conducted under controlled conditions to assess the behavior of three widely used, low-cost GNSS receivers when subjected to jamming signals. Their response to single-frequency, multifrequency, and broadband FM-modulated interference was examined and analyzed across six distinct jamming power levels. The findings are visually presented through the temporal evolution of the average code-to-noise ratio, the number of satellites utilized for positioning, and the effect of jamming on location accuracy, observed as the deviation from a known reference point. The results reveal unpredictable behavior in GNSS receivers, highlighting the need for rigorous statistical analysis. Consequently, the paper proposes a suitable methodological framework for evaluating receiver vulnerability, applicable to measurements obtained in simulated environments or using extended sequences of real-world signalsSatelitska navigacija je temelj sodobnih tehnologij, vse od naprednih avtonomnih vozil do telekomunikacijskih omrežij naslednje generacije. Čedalje večje zanašanje gospodarstva na zanesljivo delovanje globalnih navigacijskih satelitskih sistemov (GNSS) ustvarja ranljivo točko za izvedbo zlonamernega napada z željo po prekinitvi delovanja njihovih sprejemnikov. Napad sam po sebi ni kritičen, če je uporabnik o tem ustrezno obveščen; težava nastane, ko namerna motnja povzroči poslabšanje zanesljivosti ustvarjenih informacij (položaja in časa), ne pa tudi popolne odpovedi navigacijskega sistema. Temu se kljub uporabi najsodobnejših sprejemnikov GNSS ni mogoče povsem izogniti. To delo obravnava kar 400-odstotno letno rast števila namernih napadov GNSS z motnjami, predstavi tehnološke protiukrepe za zmanjševanje njihovih posledic in poda priporočila končnim uporabnikom za gradnjo odpornejših sprejemnikov. Rezultati meritev treh sprejemnikov GNSS v nadzorovanih laboratorijskih pogojih potrjujejo nedeterminističen odziv na motnje, ki ga je mogoče ovrednotiti zgolj z uporabo več merilnih vzorcev v daljšem časovnem obdobju. Prispevek vzpostavlja novo metodologijo za ustrezno sistematično vrednotenje odziva s pomočjo simulacijskega okolja ali dolgotrajnega opazovanja resničnih signalovTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaElektrotehniška zveza Slovenije