Magnetotelluric two-dimensional inversion method based on tabu search

Abstract

The invention discloses a magnetotelluric two-dimensional inversion method based on tabu search. The method comprises the steps of building a resistivity tabu search list through employing the drilling, logging, geological plotting and regional geologic map, proposing a tabu search principle, and reducing the resistivity parameter search range before magnetotelluric inversion iteration, constructing an inversion initial model according to the tabu search table, then performing two-dimensional forward modeling and residual error calculation, then judging whether a target function sets a minimum value or not, and if so, outputting stratum resistivity and thickness values, and if not, modifying the inversion model according to the sensitivity matrix, and continuously iterating until the target function reaches a set minimum value. An interchange theorem is adopted in sensitivity matrix calculation, grid nodes and measuring points are interchanged, forward modeling one-time solving is utilized, the sensitivity of multiple nodes is obtained, the calculated amount is reduced, and the accuracy and inversion efficiency of an inversion result are improved.

Description

technical field [0001] The invention belongs to the technical field of railway engineering geophysical exploration, and in particular relates to a two-dimensional magnetotelluric inversion method based on tabu search. Background technique [0002] At present, the magnetotelluric method is mostly used for geological survey work in railway tunnels, but the current use of magnetotelluric data for drilling and surveying and mapping is still at the stage of inversion initial model establishment and result verification, and the information has not been applied to the inversion iteration process; At the same time, the calculation speed of the inversion sensitivity is slow, which greatly affects the implementation of the inversion, so it is necessary to increase the calculation speed of the sensitivity. Contents of the invention [0003] In order to solve the above-mentioned problems in the prior art, the present invention provides a two-dimensional magnetotelluric inversion metho...

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Problems solved by technology

[0002] At present, the magnetotelluric method is mostly used for geological survey work in railway tunnels, but the current use of magnetotelluric data for drilling and surveying and mapping is still at the stage of inversion initial model establishment and result verification, and the information has not been applied to the inversion iteration process; At the same time, the calculation speed of the inversion sensitivity calculation is slow, which greatly affects the implementation of the inversion, so it is necessary to increase the calculation speed of the sensitivity

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