CN-122021133-A - Method and equipment for forward modeling by simulating undulating terrain

CN122021133ACN 122021133 ACN122021133 ACN 122021133ACN-122021133-A

Abstract

The invention discloses a method and equipment for forward modeling of a simulated undulating terrain, wherein the method comprises the steps of establishing a curved coordinate system according to a target undulating terrain form, obtaining curved coordinate coefficients of calculation nodes under the curved coordinate system, setting electromagnetic parameters required by forward modeling, splitting radar wave equation under the curved coordinate system to obtain a plurality of split equations capable of being calculated independently, optimizing deployment positions of electric field strength and magnetic field strength in staggered grids according to the curved coordinate coefficients and structures of the split equations, enabling the staggered grids to adapt to space features and the curved coordinate coefficients of the curved coordinate system, calculating the staggered grids respectively for each split equation, recombining and adding calculation results of each split equation, and storing the calculation results in grid units according to a staggered rule to realize high-precision forward modeling of the undulating terrain. The invention can effectively avoid the stepped corner points and the derived dispersion and scattering problems generated when the regular grid simulates the undulating topography, and greatly improve the wave field simulation precision.

Inventors

Zheng jinxin
LUO FENG
WANG LINFEI
SHU QING
LI XINGSU
Teng Deliang

Assignees

中国自然资源航空物探遥感中心

Dates

Publication Date: 20260512
Application Date: 20260108

Claims (10)

1. A method of simulating a relief feature for forward modeling, the method comprising: establishing a curved coordinate system according to the target relief topography form, and acquiring curved coordinate coefficients of all calculation nodes in the curved coordinate system; Setting electromagnetic parameters required by forward modeling, and splitting a radar wave equation under the curved coordinate system to obtain a plurality of split equations capable of being calculated independently; optimizing the deployment positions of the electric field strength and the magnetic field strength in the staggered grid according to the curved coordinate coefficient and the structure of the splitting equation, so that the staggered grid is adapted to the spatial characteristics of the curved coordinate system and the curved coordinate coefficient; And respectively carrying out staggered grid calculation on each split equation, recombining and adding calculation results of each split equation, and storing the calculation results in grid cells according to a staggered rule to realize high-precision forward modeling of the undulating terrain.
2. A method for forward modeling of simulated relief terrain according to claim 1, wherein the specific method for establishing a curved coordinate system based on the target relief terrain morphology is: and constructing a curved coordinate system according to the surface profile characteristics of the target relief topography by adopting a body-attached coordinate transformation mode, so that the boundary of the curved coordinate system is attached to the surface profile of the target relief topography.
3. The method for forward modeling of simulated relief terrain according to claim 1, wherein the specific method for obtaining the curved coordinate coefficients of each calculation node in the curved coordinate system is as follows: And obtaining the curved coordinate coefficient of each calculation node by solving an equation set meeting the preset boundary condition, wherein the curved coordinate coefficient reflects the grid bending degree and the coordinate transformation relation of the corresponding node.
4. A method for simulating a relief terrain for forward modeling according to claim 1, wherein the specific method for setting the electromagnetic parameters required for forward modeling is as follows: The electromagnetic parameters comprise dielectric coefficient, conductivity and permeability of the medium, and the numerical values of the parameters are determined by referring to the measured data of the physical characteristics of the actual medium corresponding to the target topography.
5. A method for simulating a relief terrain for forward modeling according to claim 1, wherein the specific method for setting the electromagnetic parameters required for forward modeling is as follows: when electromagnetic parameters are set, the accuracy requirement of forward modeling is combined, rationality verification is carried out on parameter values, and abnormal values exceeding the physical characteristic range are removed.
6. A method of modeling undulating terrain for forward modeling according to claim 1, wherein the specific method of splitting the radar wave equation in the curved coordinate system is: the physical rule of wave field propagation is followed during the split equation, the original wave equation is split into two split equation structures which can be independently solved, and the space characteristic information of a curved coordinate system is not lost after the split.
7. The method for forward modeling of simulated undulating terrain according to claim 1, wherein the specific method for optimizing the deployment positions of the electric field strength and the magnetic field strength in the staggered grid according to the curved coordinate coefficient and the structure of the split equation is as follows: the electric field intensity is deployed at 1/4 node of the grid, the magnetic field intensity is deployed at the whole node of the staggered grid, and the deployment positions are matched with the curved coordinate coefficient characteristics of the corresponding nodes one by one.
8. A method for forward modeling of simulated undulating terrain as claimed in claim 1, wherein said specific method for respectively performing staggered grid computation on each split equation is as follows: And in the calculation, a curved coordinate coefficient is used as a reference, and a second-order precision differential calculation logic is adopted, so that calculation errors caused by grid bending are reduced.
9. A method for forward modeling of simulated undulating terrain according to claim 1, wherein the specific method for recombining and adding the calculation results of each split equation and storing the calculation results in the grid cells according to the interleaving rule is as follows: and respectively summarizing the results of each splitting equation according to the types of the physical quantities of the electric field intensity and the magnetic field intensity during recombination, and keeping consistent deployment positions after optimization during storage, so as to reserve a data calling interface for subsequent iterative computation.
10. An apparatus for simulating a relief feature for forward modeling, the apparatus comprising: one or more processors; Storage means for storing one or more programs which when executed by the one or more processors cause the one or more processors to implement a method of simulating a relief topography as claimed in any one of claims 1 to 9 for forward modeling.

Description

Method and equipment for forward modeling by simulating undulating terrain Technical Field The invention relates to the technical field of earth exploration, in particular to a method and equipment for forward modeling by simulating undulating terrain. Background The geological radar is a geophysical detection means for shallow exploration according to electromagnetic medium differences, has the characteristics of simple operation, light instrument, high resolution and the like, and is widely applied to the fields of shallow geological identification and prediction, quality detection, engineering detection, environmental protection, geological disasters and the like. Along with the increase of the high-precision wave field simulation requirements of geological radars, radar wave conduction is influenced by surface fluctuation and needs to be brought into a simulation category. The conventional undulating topography simulation mostly adopts regular grids, stepped angular points are artificially introduced in the mode, so that the frequency dispersion phenomenon occurs in the wave field simulation process, the simulation precision is seriously affected, while curved grids can be better attached to the actual surface undulating form, the angular points are prevented from being introduced, in the conventional forward wave field simulation, the staggered grid calculation format with better stability cannot be adapted due to the fact that new parameters are introduced by a curved coordinate system. Therefore, how to adopt staggered grids to realize forward simulation of radar waves under a curved coordinate system, the problems of angular point scattering and frequency dispersion of regular grids are overcome, and the simulation precision of the undulating topography wave field is improved, so that the method is a technical problem to be solved currently. The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art. Disclosure of Invention The invention aims to provide a forward modeling method and equipment for modeling undulating terrain, which are used for optimizing the deployment positions of electric field strength and magnetic field strength in staggered grids and finishing a calculated recombination result by establishing a curved coordinate system attached to the undulating terrain of a target and a radar wave equation under a split curved coordinate system so as to solve the technical problems that wave field dispersion and modeling accuracy are low due to the fact that stepped corner points are introduced when the regular grid models the undulating terrain at present, and a conventional staggered grid cannot be matched with the curved coordinate system. To achieve the above object, the present invention provides a method for simulating a relief terrain for forward modeling, the method comprising: establishing a curved coordinate system according to the target relief topography form, and acquiring curved coordinate coefficients of all calculation nodes in the curved coordinate system; Setting electromagnetic parameters required by forward modeling, and splitting a radar wave equation under the curved coordinate system to obtain a plurality of split equations capable of being calculated independently; optimizing the deployment positions of the electric field strength and the magnetic field strength in the staggered grid according to the curved coordinate coefficient and the structure of the splitting equation, so that the staggered grid is adapted to the spatial characteristics of the curved coordinate system and the curved coordinate coefficient; And respectively carrying out staggered grid calculation on each split equation, recombining and adding calculation results of each split equation, and storing the calculation results in grid cells according to a staggered rule to realize high-precision forward modeling of the undulating terrain. In one embodiment of the present invention, the specific method for establishing the curved coordinate system according to the target relief topography is as follows: and constructing a curved coordinate system according to the surface profile characteristics of the target relief topography by adopting a body-attached coordinate transformation mode, so that the boundary of the curved coordinate system is attached to the surface profile of the target relief topography. In an embodiment of the present invention, the specific method for obtaining the curved coordinate coefficient of each calculation node in the curved coordinate system includes: And obtaining the curved coordinate coefficient of each calculation node by solving an equation set meeting the preset boundary condition, wherein the curved coordinate coefficient reflects