An Experimental Study of Passive UAV Tracking with Digital Arrays and Cellular Downlink Signals

TL;DR

This paper presents a passive UAV tracking system using digital antenna arrays and LTE signals, achieving meter-level accuracy in urban environments through bistatic signal analysis and multi-target tracking.

Contribution

It introduces a novel passive UAV tracking method leveraging LTE signals and digital arrays, with a multi-target framework for improved accuracy and reliability.

Findings

Achieves meter-level tracking accuracy in experiments.

Effectively detects bistatic range, Doppler shift, and AoA of UAVs.

Demonstrates feasibility of passive tracking using existing cellular infrastructure.

Abstract

Given the prospects of the low-altitude economy (LAE) and the popularity of unmanned aerial vehicles (UAVs), there are increasing demands on monitoring flying objects at low altitude in wide urban areas. In this work, the widely deployed long-term evolution (LTE) base station (BS) is exploited to illuminate UAVs in bistatic trajectory tracking. Specifically, a passive sensing receiver with two digital antenna arrays is proposed and developed to capture both the line-of-sight (LoS) signal and the scattered signal off a target UAV. From their cross ambiguity function, the bistatic range, Doppler shift and angle-of-arrival (AoA) of the target UAV can be detected in a sequence of time slots. In order to address missed detections and false alarms of passive sensing, a multi-target tracking framework is adopted to track the trajectory of the target UAV. It is demonstrated by experiments that the proposed UAV tracking system can achieve a meter-level accuracy.