Three-dimensional magnetotelluric tipper inversion method using nonlinear conjugate gradients

Abstract

The invention provides a three-dimensional magnetotelluric tipper inversion method using nonlinear conjugate gradients and belongs to the technical field of magnetotelluric sounding. The method comprises steps as follows: S1, inputting data and performing ranking; S2, distributing the parameter of each frequency point to all cpus for tipper inversion and computing; S3, stopping parallel computing and combining the data, and comparing the difference between an invention result and the input date; S4, distributing the data difference and the parameter of each frequency point to all cpus for parallel computing of objective function gradients, computing the search direction p and the step length a and accordingly obtaining a model modification amount; S5, updating a module according to the model modification amount and stopping iteration when an objective function is one hour enough, otherwise, using a new model to repeat the steps from S2 to S5. According to the inversion method, tipper three-dimensional inversion is realized on the basis of tipper data by introducing a nonlinear conjugate gradient method, and the invention result approaches to real underground three-dimensional electrical structure information greatly; the method adopts a parallel computing structure, and the computing efficiency is improved.

Description

Technical field [0001] The invention relates to the technical field of magnetotelluric sounding, in particular to a three-dimensional dipon inversion method of magnetotelluric field nonlinear conjugate gradient. Background technique [0002] Magnetotelluric sounding methods are widely used in deep geological exploration and exploration of resources such as minerals, water, petroleum, and geothermal. At present, two-dimensional inversion is the mainstream method of data interpretation. There are few studies on three-dimensional inversion methods. For impedance data, foreign scientists have proposed fast relaxation methods and conjugate gradient methods. Less research. [0003] In modern geophysical methods that use natural electromagnetic fields for exploration, there are two main methods for collecting vertical magnetic field components: (1) Magnetotelluric sounding (MTS) that simultaneously collects electric and magnetic signals: Observes electric fields in two horizontal directi...

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Problems solved by technology

[0015] However, the above algorithm has the following defects and deficiencies: (1) the calculation efficiency is relatively slow

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