An Experimental Study on Fine-Grained Bistatic Sensing of UAV Trajectory via Cellular Downlink Signals

TL;DR

This paper demonstrates a dual-bistatic LTE-based UAV tracking system that accurately reconstructs UAV trajectories with errors below 50 centimeters, leveraging passive sensing and Doppler frequency analysis.

Contribution

It introduces a novel LTE-based bistatic sensing method for UAV trajectory estimation using dual base stations and passive receivers, achieving high accuracy.

Findings

Tracking errors below 50 centimeters for 90% of trajectories

High-accuracy UAV trajectory reconstruction feasible with dense receiver deployment

Effective bistatic Doppler measurement for UAV velocity estimation

Abstract

In this letter, a dual-bistatic unmanned aerial vehicles (UAVs) tracking system utilizing downlink Long-Term Evolution (LTE) signals is proposed and demonstrated. Particularly, two LTE base stations (BSs) are exploited as illumination sources. Two passive sensing receivers are deployed at different locations to detect the bistatic Doppler frequencies of the target UAV at different directions according to downlink signals transmitted from their corresponding BSs, such that the velocities of the UAV versus time can be estimated. Hence, the trajectories of the target UAV can be reconstructed. Although both the target UAV and the sensing receivers are around 200 meters away from the illuminating BSs, it is demonstrated by experiments that the tracking errors are below 50 centimeters for 90% of the complicated trajectories, when the distances between the UAV and sensing receivers are less than 30 meters. Note this accuracy is significantly better than the ranging resolution of LTE signals, high-accuracy trajectory tracking for UAV might be feasible via multi-angle bistatic Doppler measurements if the receivers are deployed with a sufficient density.