DragonFly: Single mmWave Radar 3D Localization of Highly Dynamic Tags in GPS-Denied Environments

2025-07-06

AI Summary

To address the challenge of three-dimensional (3D) localization of high-speed dynamic targets (e.g., personnel, vehicles, UAVs) in GPS-denied indoor environments, this paper proposes a passive backscatter tracking system based on a single MIMO millimeter-wave radar. The system achieves, for the first time, long-range (up to 50 m) 3D localization of millimeter-scale backscatter tags operating under high acceleration (≤4 m/s²) and high velocity (≤10 m/s). Key innovations include: (1) a Doppler de-aliasing algorithm to resolve velocity ambiguity induced by high-speed motion; and (2) a fully integrated cross-polarized dielectric lens tag, consuming only 68 μW while significantly enhancing reflection efficiency and angular robustness. Experimental evaluation demonstrates a median 3D localization accuracy of 12 cm in both static and quadrotor flight scenarios. This work establishes a new paradigm for low-power, high-precision indoor spatial awareness.

Technology Category

• Intelligent Robots: Localization, Mapping, and Navigation
• Computer Vision: Motion & Tracking
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Security and Privacy: Large-scale security measurements
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation

Abstract

The accurate localization and tracking of dynamic targets, such as equipment, people, vehicles, drones, robots, and the assets that they interact with in GPS-denied indoor environments is critical to enabling safe and efficient operations in the next generation of spatially aware industrial facilities. This paper presents DragonFly , a 3D localization system of highly dynamic backscatter tags using a single MIMO mmWave radar. The system delivers the first demonstration of a mmWave backscatter system capable of exploiting the capabilities of MIMO radars for the 3D localization of mmID tags moving at high speeds and accelerations at long ranges by introducing a critical Doppler disambiguation algorithm and a fully integrated cross-polarized dielectric lens-based mmID tag consuming a mere 68 uW. DragonFly was extensively evaluated in static and dynamic configurations, including on a flying quadcopter, and benchmarked against multiple baselines, demonstrating its ability to track the positions of multiple tags with a median 3D accuracy of 12 cm at speeds and acceleration on the order of 10 m/s-1 and 4 m/s-2 and at ranges of up to 50 m.

Problem

• 3D localization of dynamic tags without GPS
• Tracking fast-moving objects with mmWave radar
• High-accuracy positioning in indoor industrial environments

Innovation

• Single MIMO mmWave radar for 3D localization
• Doppler disambiguation algorithm for high-speed tags
• Cross-polarized dielectric lens-based mmID tag