Locating GNSS Interference Sources using ADS-B with Non-linear Least Squares

Global navigation satellite systems (GNSS) support safety-of-life aviation applications, including precise navigation during aircraft approach and landing. However, signal interference near airports can severely impair operational availability and integrity, and traditional methods for interference detection are generally costly and time-consuming to implement over large areas. In this paper, we develop a novel algorithm that uses Automatic Dependent Surveillance–Broadcast (ADS-B) reports, which are routinely transmitted by aircraft and publicly available, to estimate interference power and the geographic location of a GNSS interference source. We then test the algorithm on recorded ADS-B transmissions from a 2022 interference event at Denver International Airport (KDEN). Results show that the algorithm successfully detects interference and localizes the source within a 0.1-degree error margin in latitude and longitude. Unlike previous interference detection methods, our algorithm also quantifies uncertainty through error bounds and probability heatmaps, enhancing the reliability and interpretability of the results. Overall, this algorithm can help narrow the ground search area and support the physical shutdown of GNSS interference sources.