2.5‐Dimensional Electrical Resistivity Tomography for Cylindrical Objects Incorporating the Wavenumbers Selected by the Modified Optimization Method

Applications of electrical resistivity tomography (ERT) for cylindrical objects have been rising in recent decades, yet the existing 2.5‐dimensional (2.5D) ERT schemes incorporating wavenumbers selected by the modified optimization method exhibit significant modelling inaccuracies. This study introduces a 2.5D ERT method for cylindrical objects incorporating the wavenumbers selected by the modified optimization method, which is derived based on the approximate analytic solution of the circumference potential distribution of an infinitely long homogeneous cylindrical model and can achieve more precise 2.5D potential field computations. The method combines finite element method (FEM) with unstructured meshes for geometrical flexibility and introduces a differential resistivity reconstruction method to maintain computational efficiency. Laboratory validations using NaCl solution‐filled cylindrical tanks with/without central resistive bars demonstrate up to about 60% error reduction compared to conventional approaches. The differential resistivity reconstruction achieves sub‐5‐s inversion times with high spatial accuracy in anomaly localization. This advancement establishes a robust foundation for ERT applications in biomedical imaging, infrastructure monitoring and environmental studies involving cylindrical geometries.