Three‑dimensional fast inversion of gravity and its gradient tensor data in wavenumber domain

Abstract

The gravitational potential field plays a pivotal role in interdisciplinary geological exploration. Recently, significant progress has been made in inversion techniques for three‑dimensional gravity anomaly and its gradient tensor data in the spatial domain. However, in geoscientific research, gravity anomalies derived from models such as the Earth Gravitational Model (EGM) and other
characteristic series models are prevalent. These spherical harmonic models have limitations due to their finite order, which can lead to truncation errors when traditional spatial domain inversion methods are applied. To address this problem, this paper presents a novel inversion method for three‑dimensional gravity and its gradient tensor data in the wavenumber domain. Unlike the spatial domain inversion, the Green’s function matrix in the wavenumber domain is sparse, resulting in substantial improvements in computational efficiency and reduced calculation time. Furthermore, to tackle the issue of multiple solutions often encountered in wavenumber domain inversions, regularization techniques commonly used in the spatial domain have been incorporated. This strategic integration stabilizes the inversion process and enhances the reliability of the results. To validate the effectiveness of the proposed method, rigorous testing using theoretical model data and field data has been performed. The inversion results clearly demonstrate the robustness of this novel approach, making it highly suitable for inverting three‑dimensional gravity anomalies
and their gradient tensor data.