Modeling of Bandpass GPR Problem by HIE Procedure with Enhanced Absorption

For geoscience problem whose structures are complex and fine along a single direction, hybrid implicit-explicit (HIE) procedure is incorporated with the complex envelope (CE) method in bandpass circumstance. In ground-penetrating radar (GPR) simulation, large amount of low-frequency waves results in unacceptable performance especially in low frequency. To alleviate such phenomenon, higher order concept is introduced into perfectly matched layer (PML) formulation. The efficiency, accuracy, and absorption are illustrated through numerical examples. It can be concluded that the proposed procedure can receive better efficiency, considerable absorption, and remarkable accuracy. Such condition indicates the proposed scheme takes advantages over the afore-mentioned schemes which show its potential in the bandpass GPR problems. Most importantly, it can solve two pivotal issues: 1) it can alleviate time increment problem of the implicit algorithms with small time step and 2) it can keep the unconditional stability with the increment of time steps.