Ohio State University researchers have developed an algorithm that can “eavesdrop” on any signal from a satellite and use it to locate any point on Earth, much like GPS.

The study represents the first time an algorithm was able to exploit signals broadcast by multi-constellation low Earth orbit satellite (LEO) satellites, namely Starlink, OneWeb, Orbcomm and Iridium.

During an experiment to test how the signals worked as an accurate positioning system, researchers set a ground receiver’s initial position estimate to the roof of an engineering parking structure at the University of California, Irvine, a spot more than 2,000 miles away from the researchers in Columbus, Ohio. Using the satellite constellations to guess where exactly in the country the receiver actually was, the algorithm was only off by about 5 meters.

https://news.osu.edu/this-algorithm-can-make-satellite-signals-act-like-gps/
https://people.engineering.osu.edu/sites/default/files/2023-05/Kassas_Multi_constellation_blind_beacon_estimation_Doppler_tracking_and_opportunistic_positioning_with_OneWeb_Starlink_Iridium_NEXT_and_Orbcomm_LEO_satellites.pdf