Low-frequency method of miners searching in case of rock collapse

Introduction. This article addresses the critical issue of locating miners following emergencies in mines, particularly those caused by rock collapses. It explores the potential of utilizing electromagnetic beacons for effective search and rescue operations. Purpose of the Research. The study prioritizes systems that employ low-frequency electromagnetic fields (VLF) within the 1–300 kHz range for accurate coordinate determination. The authors propose the use of individual active magnetic beacons, designed with solenoidshaped radiating antennas, to facilitate the search for trapped miners. Materials and Methods. The location of the beacon is established by capturing its magnetic field components through three mutually perpendicular receiving antennas. The research involved analyzing the spatial distribution of these magnetic field components, with findings aligning closely with theoretical predictions. Results. Experimental data and digital simulations revealed insights into the magnetic field distribution from the solenoid in both open spaces and mine workings. Notably, amplitude-frequency characteristics were recorded at a distance of 22 meters under varying rock conditions. Discussion. The study highlights that higher operating frequencies can lead to increased errors in distance estimation due to non-uniform electrical conductivity in rocks. A single-component antenna proves inadequate for precise localization, as it lacks comprehensive data from other field components. Conclusion. Employing a magnetic beacon for miner localization during emergencies is most effective at low frequencies (8 kHz), which demonstrate resilience against rock interference. Resume. Utilizing three orthogonal antennas for comprehensive registration of the beacon’s magnetic field components enhances vector determination and minimizes coordinate estimation errors. To further refine coordinate accuracy, implementing a threecomponent receiving antenna is recommended. Additionally, exploring a differential method for coordinate measurement across multiple points could yield significant improvements in search efficiency.