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 signals
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