Gravity magnetic field imaging method and system

Abstract

The invention provides a gravity magnetic field imaging method and system. The method comprises the following steps: calculating all orders of vertical guide numbers {Tn} of gravitational magnetic field data by utilizing an integrated quadratic vertical guide number method; substituting the actually measured first-order vertical derivative into the method for integrating the second-order vertical derivative, and degrading the method for integrating the second-order vertical derivative into a method which only needs to calculate in a spatial domain without solving a heavy magnetic field integral in a wavenumber domain; calculating a coefficient equation of Pade approximate expansion downward continuation by utilizing the obtained vertical guide number {Tn} of each order, and solving coefficients in the coefficient equation; substituting the obtained coefficient into Pade approximate expansion, and calculating a downward continuation result of the gravity magnetic field data; and performing median filtering on the obtained downward continuation result, and directly imaging the filtered result to obtain an equivalent gravity magnetic field imaging result. The gravity magnetic field imaging method and system provided by the invention can be used for improving the accuracy and reducing the dependence on depth weighting on the premise of ensuring the stability.

Description

technical field [0001] The present invention relates to the technical field of earth detection and information, in particular to a method and system for imaging of gravity and magnetic fields. Background technique [0002] Gravity and magnetic field imaging technology is the main means for efficient modeling of the gravity and magnetic field inside the earth, and the overall requirement for establishing the density and magnetic model of the earth's interior is high accuracy, and the requirements for the modeling of gravity and magnetic field imaging are also high accuracy. However, there are certain problems in the existing gravity and magnetic field imaging related technologies. First, since the current gravity and magnetic field data imaging method is based on upward continuation, this technology has the property of low-pass filtering, which can ensure the stability and accuracy of data processing. However, due to this property, the effective information in the high-freque...

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Problems solved by technology

However, there are certain problems in the existing gravitational and magnetic field imaging related technologies that have been carried out: first, because the current gravitational and magnetic field data imaging method is based on upward continuation, this technology has low-pass filtering properties to ensure the stability and accuracy of data processing, However, due to this attribute, the effective information of the high-frequency part of the data will also be suppressed, resulting in insufficient extraction of effective information and insufficient accuracy of the data used for modeling; Depth weighting is adopted, and the setting of depth weighting parameters directly affects the accuracy of imaging results. In theory, to obtain the type of gravity and magnetic field target in advance, it needs to be known in advance through other means, which complicates the imaging process, and is different from the gravity and magnetic field imaging technology in construction. Contradictory to the advantage of efficiency in terms of modeling

[0011] It is not difficult to see that, using the DEXP method based on upward continuation to image the gravitational and magnetic field, the key lies in the depth weighting And this critical amount requires a lot of preliminary work, which affects the rapid imaging of gravity and magnetic field

And this method is based on upward continuation. Although the general upward continuation method is stable and accurate, its inherent low-pass filtering and smoothing effect will lose the detailed information in the gravity and magnetic field data.

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