Three-dimensional gravity forward modeling method and system based on residual density model

Abstract

The invention relates to a three-dimensional gravity forward modeling method and system based on a residual density model, and the method comprises the steps: constructing a density interface model subdivision grid, setting a model boundary condition, calculating a non-zero value residual node density model, calculating a gravity abnormal value of a specified point, and optimizing a calculation process through introducing the residual density model. According to the method, the redundant calculation amount in the calculation process is reduced, the spatial domain density interface gravity anomaly forward modeling calculation efficiency can be remarkably improved, meanwhile, it is guaranteed that the calculation precision can be comparable with a frequency domain forward modeling method and a spatial domain forward modeling method, and an efficient algorithm is provided for super-large-scale geology-geophysics gravity field simulation.

Description

technical field [0001] The invention relates to the technical field of three-dimensional gravity model calculation, in particular to a three-dimensional gravity forward modeling method and system based on a residual density model. Background technique [0002] In the prior art, the gravity anomaly forward modeling of the three-dimensional density interface can be divided into the frequency domain forward modeling method and the space domain forward modeling method. [0003] The frequency domain forward modeling method is mainly based on the interface anomaly calculation formula proposed by Parker and a series of generalized forms. Due to the use of FFT algorithm, the frequency domain method has the advantage of fast calculation speed in the forward modeling of gravity anomalies in deep interfaces, and has a wide range of applications. After several years of development, this method can be applied to a variety of variable density interface models, and has been widely used and...

AI Technical Summary

Problems solved by technology

Due to the use of FFT algorithm, the frequency domain method has the advantage of fast calculation speed in the forward modeling of gravity anomalies in deep interfaces, and has a wide range of applications. After several years of development, this method can be applied to a variety of variable density interface models, and has been widely used and developed. However, the frequency domain calculation method is only suitable for the case where the observation surface is horizontal, and the calculation points must be consistent with the model subdivision grid. Calculation of gravity anomalies at any point on the undulating surface, the scope of application is limited

[0004] The space domain forward modeling method usually uses upright hexahedrons to subdivide the density interface model, and then calculates the gravity anomaly caused by each subdivision unit at the calculation point according to the upright hexahedron gravity anomaly forward modeling formula, and finally all subdivision units in the calculation The gravity anomaly caused by the point can be superimposed and summed to obtain the gravity anomaly at the calculation point. This type of method has the characteristics of high calculation accuracy and wide application range, and can be applied to almost all density interface forward modeling situations without limiting the observation point. The position and density interface shape characteristics are suitable for accurately simulating the gravity anomaly response of complex interface shapes. However, since the existing space domain forward calculation method needs to calculate the gravity anomaly of all point sources when calculating the gravity anomaly of each observation point, When there are many calculation points and subdivided point sources, the amount of calculation is large, so there are disadvantages of low calculation efficiency and slow calculation speed, which cannot be used for simulation calculations of ultra-large-scale models, especially it is difficult to meet the requirements of ultra-large-scale fine density interface models Gravity Field Simulation Requirements

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