Method of locating coal-rock main fracture by electromagnetic radiation from precursor of coal-rock dynamic disaster

A method of locating a coal-rock main fracture by an electromagnetic radiation from a precursor of a coal-rock dynamic disaster, comprising of the following steps:

• step 1, collecting three-component electromagnetic signals generated by downhole coal-rock fractures, by using at least four groups of non-coplanar three-component electromagnetic sensors arranged in underground tunnels, and ensuring that the non-coplanar three-component electromagnetic sensors in different groups receive the three-component electromagnetic signals synchronously via an atomic clock;
• step 2, analyzing frequency spectrums of the three-component electromagnetic signals collected by the at least four groups of non-coplanar three-component electromagnetic sensors, and recognizing and ensuring the three-component electromagnetic signals received by the at least four groups of non-coplanar three-component electromagnetic sensors are from a same main fracture by a signal frequency criterion;
• step 3, performing a vector superposition on strengths of the three-component electromagnetic signals received by the at least four groups of non-coplanar three-component electromagnetic sensors to determine a direction of a magnetic field line at each of a plurality of positions where each group of sensors of the at least four groups of non-coplanar three-component electromagnetic sensors is located;
• step 4, determining at least one plane of electromagnetic wave propagation according to the direction of the magnetic field line at the position where each group of sensors is located, wherein an electromagnetic wave is perpendicular to the direction of the magnetic field line;
• and
• step 5, determining an intersection point of the at least one plane of electromagnetic wave propagation as a location of an electromagnetic radiation source, wherein the at least one plane of electromagnetic wave propagation are determined by the at least four groups of non-coplanar three-component electromagnetic sensors, and the location of the electromagnetic radiation source is an area of the coal-rock main fracture of a precursor of the coal-rock dynamic disaster.