Research on Electromagnetic Scattering of Buried Cables Based on FDTD Algorithm

The detection of buried cables is an important technology, and the research on the electromagnetic scattering characteristics of buried cables is its theoretical basis. In this paper, based on the two-dimensional Finite-Difference Time-Domain (FDTD) method, the surface current using Gaussian pulse waveform is used as the excitation source, and when the buried depth is constant, the half-space models of buried cables under several typical working conditions are established. The influence of these factors on the electromagnetic scattering characteristics is analyzed respectively. Results show that the increase of soil humidity will weaken the incident wave. When the humidity ranges from 0.1g/cm
³
to 0.4g/cm
³
, the maximum magnitude decreases by about 12dB in turn. The coupling effect will occur when the cables are laid in parallel, and when the distance changes, it will affect the phase of the electric field at the collection point, but has little effect on the magnitude. After adding a layer of concrete cover of 50mm thickness, there is no significant change, but the phase is shifted forward. In this paper, the cylindrical wave is generated by the surface current source, which reduces the calculation and programming complexity compared with the traditional way of introducing plane waves at the TF-SF boundary. This paper provides ideas and guidance for the accurate detection and imaging of buried cables.