Robust Full Waveform Inversion Using Normalized Residual in the Frequency Domain

A robust objective function for the full waveform inversion has been suggested in the frequency domain. The proposed objective function is defined as sum of complex absolute values of residual wavefields in the frequency domain. Generally, the full waveform inversion is extremely sensitive to the parameterization, frequency bandwidth, attenuation, noise and so on. Especially, noise is the most important factor in the full waveform inversion. In the frequency-domain waveform inversion, the attenuation of wavefields is one of the critical parameters for successful inversion. To verify the robustness of our algorithm, the proposed inversion scheme was tested in terms of the sensitivity to attenuation and noise. The comparison examples with both the conventional l2-norm and the logarithmic objective function demonstrated that the proposed inversion algorithm is robust to noise and less sensitive to attenuation.