Vertical Fracture Strike Angle Estimation Based on Cameron Decomposition of Full-Polarimetric Ground-Penetrating Radar

The strike of vertical fractures is a key geometric parameter for interpreting subsurface structures. However, conventional single-polarimetric ground-penetrating radar (SP-GPR) provides limited information on subsurface targets, making it difficult to directly estimate their horizontal strike. Although full-polarimetric ground-penetrating radar (FP-GPR) can acquire complete vector scattering responses from subsurface targets, the relationship between polarization parameters and the strike of vertical fractures has not yet been systematically investigated. This study introduces the maximum symmetric scattering component derived from the Cameron scattering decomposition into FP-GPR polarization analysis and proposes a strike estimation method based on the principal scattering axis of vertical targets. Numerical models of vertical fractures and metallic plates with different strike angles are established to evaluate the proposed method. The results demonstrate that the scattering matrix can reliably characterize the target’s principal scattering axis. However, all findings are based on numerical experiments and have not yet been validated by laboratory or field data. Furthermore, the polarization decomposition results can be directly interpreted as the geometric strike only when the target exhibits sufficiently strong scattering intensity. The scattering-intensity-weighted strike estimation achieved low mean absolute error (MAE) and root-mean-square error (RMSE) for both the metallic plate and fracture models, indicating the high accuracy of the proposed method. The method was further validated under Gaussian noise conditions, and the results show that it remains reasonably stable at certain noise levels. These findings provide numerical evidence supporting the application of the Cameron scattering decomposition to FP-GPR data for strike estimation of vertical targets.