Fast 3-D Controlled-Source Electromagnetic Modeling Combining UPML and Rational Krylov Method

Controlled-source electromagnetic (CSEM) surveying is a critical tool for sensing and locating underground anomalies and structures. In this letter, based on uniaxial perfectly matched layer (UPML) and rational Krylov (RK) method, we propose a fast algorithm for 3-D Multifrequency CSEM modeling. We use the frequency-independent UPML to truncate the boundaries and adopt an RK method to rapidly solve the 3-D multifrequency CSEM problems. The accuracy and efficiency of our algorithm are verified by two examples, i.e., a two-layer model and a 3-D model. Numerical experiments indicate that our algorithm is computationally efficient, obtaining nearly 20-fold speedup on a laptop compared with the conventional 3-D CSEM using finite element method (3DCSEM) modeling.