Evaluation of the possibility of wireless data transmission over rocks for automating an alarm system in mines using lowfrequency electromagnetic waves and radio tags

Abstract

The paper discusses the possibility of organizing a wireless data transmission channel in place of different kinds of mines for signalling and emergency communication using electromagnetic waves in the VLF propagation (300 Hz - 3 kHz). The paper gives theoretical estimates of the efficiency of propagation of electromagnetic waves in rocks and minerals with different values of electrical conductivity. The dependence of the depth of penetration on frequency is also studied. A review of the existing technical solutions to this problem is given. An analytical and numerical analysis of the current density in the rock and the magnetic field created by it using a radiating long cable is given. Reception of a signal with an informational message is carried out with the help of an individual radio tag informing personnel both in conditions of the mine's normal operation and in emergency situations. Comparative evaluations of the efficiency of using radio tags with different configurations of a receiving antenna in mine conditions at a depth of up to 800 m are given