Efficient and Low-cost Localization of Radio Signals with a Multirotor UAV

TL;DR

This paper introduces a low-cost, efficient UAV-based RF localization system that uses simple signal strength measurements and an information-theoretic controller to quickly and accurately locate radio sources with minimal calibration.

Contribution

The work presents a novel UAV system utilizing commercial components and an information-theoretic approach for rapid RF source localization, improving robustness and efficiency over prior methods.

Findings

Outperforms previous methods in localization speed

Uses low-cost commercial components for measurements

Successfully localizes diverse RF transmitters

Abstract

Localizing radio frequency (RF) sources with an unmanned aerial vehicle (UAV) has many important applications. As a result, UAV-based localization has been the focus of much research. However, previous approaches rely heavily on custom electronics and specialized knowledge, are not robust and require extensive calibration, or are inefficient with measurements and waste energy on a battery-constrained platform. In this work, we present a system based on a multirotor UAV that addresses these shortcomings. Our system measures signal strength received by two antennas to update a probability distribution over possible transmitter locations. An information-theoretic controller is used to direct the UAV's search. Signal strength is measured with low-cost, commercial-off-the-shelf components. We demonstrate our system using three transmitters: a continuous signal in the UHF band, a wildlife collar pulsing in the VHF band, and a cell phone making a voice call over LTE. Our system significantly outperforms previous methods, localizing the RF source in the same time it takes previous methods to make a single measurement.