Method for high-precision reverse time migration imaging based on severe relief surface ground penetrating radar data

Abstract

The invention relates to a method for high-precision reverse time migration imaging based on severe relief surface ground penetrating radar data. The method comprises the following steps of 1) generating a body-fitted grid discrete relief surface model; 2) decoupling from a Maxwell equation, so as to obtain a Cartesian coordinate system TM (transverse magnetic) wave equation; 3) performing reverse time extrapolation on a receiving wave field in a curvilinear coordinate system from maximum time to zero time; 4) using a sub-wave with setting certain frequency in the curvilinear coordinate system as a forward modeling sub-wave, and performing forward modeling to calculate the positive continuation wave field value at each time; 5) repeating the steps 3) and 4) on the whole profile, removing the low-frequency interference, and finally superposing, so as to obtain the complete migration profile. The method has the advantages that the frequency dispersion effect caused by the step grid at the relief surface in the Cartesian coordinate system is decreased, the interference by the low-frequency noise in the reverse time migration imaging process is favorably reduced, the reflective wave and diffracted wave in the ground penetrating radar data at the relief surface are accurately migrated and regressed, and the underground structure information is truly reflected.

Description

technical field [0001] The invention belongs to the technical field of shallow surface geological structure detection and engineering survey, and in particular relates to a high-precision reverse time migration imaging method based on ground-penetrating radar data of violently undulating surface. Background technique [0002] Aiming at problems such as oblique reflection and diffraction in ground-penetrating radar data of undulating surface areas, the undulating terrain migration method is usually used to improve the ground-penetrating radar profile and improve the resolution of migration imaging, which is used to truly and reliably identify shallow surface subsurface structures (Structure. The reverse time migration method of Cartesian coordinate system undulating surface proposed by the predecessors failed to completely solve the problem of reverse time migration imaging of ground penetrating radar data on violently undulating surface, which seriously affected the identifi...

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Problems solved by technology

[0008] In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a high-precision reverse time migration imaging method based on GPR data with severe undulations, which can avoid the above-mentioned technical defects, so as to solve the problems of GPR with severe undulations. Data high-precision reverse time migration imaging problem, improve detection resolution and reliability

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