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Gradient formula is obtained by taking the derivative of the object function with respect to the mod- el parameter�� And permittivity and conductivity are simultaneously updated by using the conjugate gradient method�� Then we apply FWI to a group of synthetic and field data�� and the results of synthetic data show that FWI can accu- rately reconstruct the value and shape of the layers and sub- wavelength anomalous bodies�� ��esults of filed data turn out that small subsurface features can be imaged and the resolution is high in the full waveform tomograms��