Abstract:

In order to get better interpretation effect, based on the theoretical analysis and formula deduction of magnetic field intensity from radio wave penetration for coal face, it is found that the variation of magnetic field intensity values are mainly controlled by the geometric positions of observation spots within the normal range of coal face, but are mainly controlled by the path length of geologic anomaly and the absorption coefficient of magnetic wave energy when the observation path of field intensity through the area of geologic anomaly. The product of magnetic field intensity H and its path length R can be named as M. Thus, the M values can be regarded as constant within the normal range of coal face, but will be greatly lowered within the abnormal range. The coal face can be divided into many units in order to carry out the computerized tomography inversion of M value; then the M values of every units will be acquired by the special software. Subsequently, with all of the inversion values divided by the average width of coal face, the image of measured field intensity for coal face can be gotten. The surveying results from Zhangji Mine had given clear geologic anomaly areas of coal face, which have been well testified by coal mining. As a new interpretation means，it has been broadly applied to radio wave penetration for coal faces.

Key words: radio wave penetration, measured field intensity, absorption coefficient, computerized tomography, geologic anomaly