Local gravity field modeling method and system based on ground gravity measurement data

Abstract

The invention provides a local gravity field modeling method and system based on ground gravity measurement data, and the method comprises the steps: collecting ground gravity observation data in a research region, carrying out the preprocessing, determining the spatial resolution of a gravity field model and the maximum expansion order of the gravity field model, carrying out the low-pass filtering of the preprocessed data, filtering out a part higher than a maximum expansion order in the ground gravity observation data to obtain filtered gravity observation data in a research area, then determining a closed boundary of the research area, obtaining an orthogonal primary function group and an optimal primary function number through calculation, obtaining an expansion coefficient of a Slepian method through calculation, consequently, obtaining a mathematical model describing the gravitational field in the research area, and finally, according to the mathematical model of the gravitational field, calculating to obtain a gravitational field signal of any point in the research area. According to the method, the problem that a classic spherical harmonic method cannot be applied in a spherical local range is solved by constructing the orthogonal basis function in the research area.

Description

technical field [0001] The invention relates to the technical field of local gravity field modeling, in particular to a local gravity field modeling method and system based on ground gravity measurement data. Background technique [0002] The earth's gravity field is the basic physical field of the earth, which reflects the distribution, movement and change of matter in the earth system. It is an important constraint for the study of the state of matter movement and its dynamic mechanism in the earth system. Pressing questions provide important basic geophysical information. Ground gravity measurement is the gravity observation carried out on land. It uses a mixed network of absolute and relative gravimeters, and obtains the change trend of the gravity field over time through regular re-measurement at the same point. The Gravity Observation System adopts this method. The advantage of ground gravity measurement lies in the good repeatability of the observation position, the...

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Problems solved by technology

[0005] In view of the problems that the actual gravity measurement data on the ground often only cover the area, and the measurement points are difficult to achieve uniform distribution in space, and the gravity field is modeled based on the ground gravity measurement data, the classical spherical harmonic analysis theory is no longer applicable, etc., the present invention provides A local gravity field modeling method based on ground gravity measurement data. By constructing an orthogonal basis function in the study area, it can effectively concentrate the spectrum energy in the study area, and solve the problem that the classical spherical harmonic method cannot be applied in the local range of the spherical surface. the puzzle

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