StarLoc: Pinpointing Transmitting LEO Satellites from a Single Passive Array

TL;DR

StarLoc is a system that accurately localizes transmitting LEO satellites in 3D space using minimal antennas by leveraging orbital dynamics and interferometric angle estimation.

Contribution

It introduces a novel interferometric 3D angle-of-arrival technique and demonstrates effective satellite localization with only three antennas.

Findings

Estimates satellite 3D angles within 0.7 degrees.

Achieves orbital range estimation within 5 km.

Validated with 81 Starlink satellite transmissions.

Abstract

This paper focuses on 3D localization of transmitting satellites in low Earth orbits (LEO). 3D localization of transmitters in low orbits is an important emerging problem for many applications such as spectrum management, orbit determination, and backup for GPS failures in orbit. We present StarLoc -- a system to geolocate transmitters in space using a combination of orbital modeling and a new interferometric 3D angle-of-arrival estimation technique. StarLoc's design relies on a unique insight -- the motion of satellites is governed by orbital dynamics and is therefore along a 2D manifold in a 3D space. This reduces the degrees of freedom in satellite motion and allows us to 3D-locate and track a satellite with just three antennas in a 2D plane. We evaluate the system using signal transmissions from 81 Starlink satellites. Our results show that StarLoc can estimate the 3D-angle of a satellite within 0.7 degrees and the orbital range within 5 km. Our dataset and implementation are available at: https://connectedsystemslab.github.io/starloc.