Waveform-Domain Three-Dimensional Localization for Time-Critical Avalanche Companion Rescue

Avalanche companion rescue provides the only realistic opportunity to locate and extricate a buried victim during the critical 10–15 min survival interval before organized rescue teams can normally arrive. Motivated by this stringent time constraint, this paper presents a physics-based waveformdomain framework for three-dimensional avalanche victim localization using a helmet-mounted Sparse Uniform Circular Array (SUCA) receiver and a compact cooperative RF beacon. Unlike conventional avalanche transceivers, which require sequential signal-search, coarse-search, and finesearch procedures, the proposed approach determines the victim’s three-dimensional coordinates directly by correlating the received waveform with a precomputed electromagnetic dictionary, enabling immediate guidance toward the estimated burial location. A comprehensive electromagnetic model incorporates realistic snow dielectric properties, propagation through snow and air, snow–air refraction, LOG-based deterministic multifrequency waveform generation, and dictionary-based localization. Numerical simulations demonstrate unique waveform representation throughout the investigated search region, complete recovery of all candidate victim locations under noiseless conditions, practical localization accuracy using a 0.5 m spatial grid, and a calculated 38 dB link margin under conservative very-wet-snow conditions. The proposed framework also supports several promising extensions beyond victim localization, including respiration monitoring, approximate body-orientation estimation, and enhanced victim detectability using passive conductive textile threads integrated into avalanche garments. Although demonstrated for avalanche companion rescue, the proposed waveform-domain localization framework represents a new operational concept for time-critical search-and-rescue and may be extended to a broad class of cooperative and non-cooperative RF sensing applications.