Joint Inversion of Electromagnetic and Acoustic Data Based on Structural Constraints with TE Illumination

Joint inversion based on the subspace-based method (JSOM) in the case of transverse magnetic (TM) waves has been proposed to combine the advantages of electromagnetic and acoustic inversion. This paper extends JSOM to reconstruct the uniaxial anisotropic scatterers by using the transverse electric (TE) waves. Compared with TM cases, the problem of inversion with TE waves is more ill-posed and more nonlinear. In the inversion process, the proposed method uses the cross-gradient function to combine the inversions of electromagnetic wave and the acoustic wave, and uses the acoustic wave data to constrain the data of the two direction components of the TE wave. Therefore, the structural similarity between the sound velocity and the permittivities of the two directions is enhanced, so that the TE wave inversion results are better. Both structure and contrast values are well reconstructed. The efficiency and the robustness of the methods are validated through numerical experiments.