Numerical modeling of borehole georadar data

摘要

High-frequency electromagnetic(EM)wave propaga- tion phenomena associated with borehole georadar ex- periments are complex. To improve our understanding of the governing physical processes, we present a finite- difference solution of Maxwell's equations in cylindrical coordinates. This approach allows us to model the full EM wavefield associated with borehole georadar exper- Iments and to assess the adequacy of ray-based meth- Ods currently used to interpret the observed amplitudes. Our results indicate that because shallow boreholes are Often water filled, the finite length of the boreholes as Well as changes in material properties along a borholes Wall can have major effects on the amplitude behavior Of borehole georadar data.