Time-Domain Physical-Optics Simulation Technique for Electromagnetic Imaging by Subsurface Radar
Abstract - This paper presents a 2-D scalar numerical time-domain (TD) model based on physical optics (PO) for simulation of electromagnetic phenomena. This TD-PO model should be applied for detection and location of objects hidden in opaque media by subsurface TD radar system. The proposed approach allows considering of basic physical principles, governing electromagnetic radiation and scattering and reception, to form electromagnetic image of subsurface region by simulation of radar returns based on TD- PO model. The TD-PO model is very preferable due to its high numerical efficiency and clear physical meaning.
Detection and localization as well as discrimination of the objects hidden in opaque media (soils, rocks, ice, brick, concrete, vegetation etc.) by subsurface radar or ground-penetrating radar (GPR) are important for worldwide scientific and engineering practice as valuable technology of remote sensing and noninvasive control , Key features of operation of impulse subsurface radar to simulate it will be considered in this paper. In general, operation of the subsurface radar is based on registration and processing of electromagnetic fields scattered by internal heterogeneity of a medium under investigation. Practical opportunities of subsurface radar to study real problems is often limited due to complexity of interpretation of scattered fields to restore original problem's geometry by processing the radar data registered.
In spite of the large amount of works on direct/inverse subsurface electromagnetic scattering, the authors were not able to locate any research where consideration of problem was preferable for own field GPR practice entirely. What is matter? Of course, there are many interest papers on GPR problems like [1,2,7]. But complex theoretical models characterize those studies for particular cases that demands high level of mathematical experience and tremendous computing efforts like for FDTD approaches. At the same time, there are also other simple simulation methods based on geometrical optics with unavoidable restrictions to apply directly for finite-sized and near-range targets where plane-wave model is incorrect etc.