Rotated staggered grid simulation and migration imaging for GPR

The paper describes the application of the rotated staggered grid(RSG) finite-difference technique to the ground penetrating radar(GPR) simulation and migration imaging in the medium possess strong heterogeneities or inhomogeneous discontinuities. The RSG use the rotated staggered finite-difference operators, to lead a distribution of GPR field components and other physical parameters in an elementary cell, in which all components of one physical property are located at one elementary unit in the computational domain, to calculate the difference of field components and physical parameters with the linear combination value of them across the diagonal coordinate axes, with the characterristics of no averaging of elementary cell even the domain possess strong heterogeneities, the paper deduced in detail for GPR rotated staggered grid finite difference scheme and the update equations, and realized the fast simulation and migration algorithms for GPR, in addition, from the perspective of migrated section at heterogeneities interface, the paper compared the standard staggered grid(SSG) difference algorithms, the high-order FDTD method and the RSG algorithms, the results shows that the RSG difference algorithms greatly improved the precision of migration imaging in diffraction section, which could effectively guide the inversion and interpretation of GPR in the medium that possess strong heterogeneities.