Study On Simulation Of Scattering Problem Of Underground Goal Object Of Ground Penetrating Radar

The efforts to model and simulate the underground goal object scattering issues raised by ground penetrating radar(GPR) are intended to improve the integrity and effectiveness of GPR and help promote its wide application. And the modeling and numeric simulation analysis also poses theoretical significance for the cases of different antenna, different underground background medium and different underground goal objects.The results can serve as guideline for ultimate imaginary analysis and antenna design of ground penetrating radar, which also paves the way for the transition from qualitative description to quantitative analysis of transient electromagnetic wave technology The underground scattering modeling and simulation of ground penetrating radar is a complicated issue. In the presence of emission and pickup of transient pulse waves generated by GPR, the Finite Difference Time Domain(FDTD) method seems to be the most proper solution. And in light of the respective strengths of Finite Difference Time Domain(FDTD) and Method of Moments in the Time Domain(MOMTD) in solving the complicated scattering and antenna radiating problems, a hybrid method may be a workable alternative to address GPR's underground scattering issues.This paper conducts the numeric analysis and simulaton of underground scattering and makes following contribution:1. Review the basic principles and techniques of Finite Difference Time Domain(FDTD) method, with special emphasis in three boundary condition namely Mur second order, Berenger perfect matching layer and Gedney perfect matching layer.2. Program and verify the Method of Moments in the Time Domain(MOMTD) by Electric Dipole simulation programs. Study the thin wire arithmetic of Finite Difference Time Domain(FDTD) method, and use it to develop a numeric simulation model of exciting sources of symmetric thin wire antennas.3. By using the symmetric thin wire antennas as the emitting and picking-up antennas, develop model and conduct simulation based on three different scattering conditions of different symmetric antenna, underground background medium and underground goal objects.4. Use the cross-section method of underground radar detecting and FDTD, develop model and conduct simulation of level diagram of different objects.