Single-Satellite-Based Geolocation of Broadcast GNSS Spoofers from Low Earth Orbit

Abstract

This paper presents an analysis and experimental demonstration of single-satellite single-pass geolocation of a terrestrial broadcast global navigation satellite system (GNSS) spoofer from low Earth orbit (LEO). The proliferation of LEObased GNSS receivers offers the prospect of unprecedented spectrum awareness, enabling persistent GNSS interference detection and geolocation. Accurate LEO-based single-receiver emitter geolocation is possible when a range-rate time history can be extracted for the emitter. This paper presents a technique crafted specifically for indiscriminate broadcast-type GNSS spoofing signals. Furthermore, it explores how unmodeled oscillator instability and worst-case spoofer-introduced signal variations degrade the geolocation estimate. The proposed geolocation technique is validated by a controlled experiment, in partnership with Spire Global, in which a LEO-based receiver captures broadcast GNSS spoofing signals transmitted from a known ground station on a non-GNSS frequency band.