Automated geolocation of diverse impulsive events using total electron content measurements

Natural impulsive events such as earthquakes, volcanic eruptions, and thunderstorms, as well as anthropogenic events such as rocket launches and atmospheric re-entries, can generate acoustic-gravity waves (AGWs) that propagate in the upper-atmosphere and produce traveling ionospheric disturbances (TIDs) observable with GNSS total electron content (TEC) measurements. We developed an algorithm for an automatic detection and geolocation of impulsive events using TEC observations of AGW-TIDs. Using observations of high-speed Falcon 9 second stage rocket re-entries over North America, we tested the algorithm on 14 events in January-May 2024. Geolocation accuracy, defined as the horizontal offset between the estimated source location and the nearest point on a simulated rocket trajectory, was 42 ± 35 km (mean ± standard deviation) across all re-entry events, with a 100 % detection rate (14/14 events). We also show that the algorithm generalizes to AGW-induced ionospheric disturbances driven by other impulsive events, including rocket launches, severe weather systems, and earthquakes. The results establish the potential to leverage TEC measurements from the ever-increasing network of GNSS receivers as passive means of near real-time monitoring and geolocation of impulsive events via the AGWs that they generate.