"Take Me Home, Wi-Fi Drone": A Drone-based Wireless System for Wilderness Search and Rescue

TL;DR

Wi2SAR is an innovative drone-based wireless system that enables long-range wilderness search and rescue by mimicking Wi-Fi networks, discovering victims' devices, and guiding drones efficiently in challenging environments.

Contribution

The paper introduces Wi2SAR, a novel autonomous drone system with three key innovations: device discovery, long-range direction finding, and adaptive navigation, all demonstrated through a working prototype.

Findings

Wi2SAR achieves high performance and efficiency in wilderness scenarios.

The system extends operational range using a 3D-printed Luneburg Lens for direction finding.

Experimental results validate Wi2SAR's practicality and effectiveness.

Abstract

Wilderness Search and Rescue (WiSAR) represents a longstanding and critical societal challenge, demanding innovative and automatic technological solutions. In this paper, we introduce Wi2SAR, a novel autonomous drone-based wireless system for long-range, through-occlusion WiSAR operations, without relying on existing infrastructure. Our basic insight is to leverage the automatic reconnection behavior of modern Wi-Fi devices to known networks. By mimicking these networks via on-drone Wi-Fi, Wi2SAR uniquely facilitates the discovery and localization of victims through their accompanying mobile devices. Translating this simple idea into a practical system poses substantial technical challenges. Wi2SAR overcomes these challenges via three distinct innovations: (1) a rapid and energy-efficient device discovery mechanism to discover and identify the target victim, (2) a novel RSS-only, long-range direction finding approach using a 3D-printed Luneburg Lens, amplifying the directional signal strength differences and significantly extending the operational range, and (3) an adaptive drone navigation scheme that guides the drone toward the target efficiently. We implement an end-to-end prototype and evaluate Wi2SAR across various mobile devices and real-world wilderness scenarios. Experimental results demonstrate Wi2SAR's high performance, efficiency, and practicality, highlighting its potential to advance autonomous WiSAR solutions. Wi2SAR is open-sourced at https://aiot-lab.github.io/Wi2SAR to facilitate further research and real-world deployment.