In this paper, the authors analyzed the suitability of 2D nonlinear conjugate inversion method in railway tunnel AMT exploration under complex topographic and geological conditions. Based on typical modeling and inversion research, researchers can find out the best key parameters to control inversion algorithm so as to avoid fake abnormalities shown on inversion results. Researches show that 2D nonlinear conjugate inversion works well in railway tunnel AMT exploration. If the true model is like the model type described in this paper, inversion result can be efficiently improved by inverting TE&TM mode data, inverting frequencies less than 1 000 Hz, using small smooth factor and choosing the half space initial model close to the shallow layers' resistivity.
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