Most existing approaches to GNSS jamming ask two questions: whether jamming is happening and how to mitigate it. This paper goes a step further and asks whether the jammer can be located using GNSS receivers alone. It presents an approach based on high-performance Septentrio GNSS receivers that needs no additional RF sensors, direction finding, cameras or other dedicated equipment. Receivers already installed on drones, vehicles or on the ground form a distributed sensor network and estimate the jammer’s position from how the interference affects their measurements. The paper describes the different effects of jamming, from degraded signal quality to loss of positioning, and explains why detection alone is not enough: knowing where the interference comes from adds situational awarene ...