Calculation of Gravity and Magnetic Source Boundaries Based on Anisotropy Normalized Variance

Abstract

AbstractFor the calculation of gravity and magnetic source boundaries, the traditional gradient methods are vulnerable to disturbance and the resulting edges may be too cluttered when the field data are affected by noise. Besides, for the weak anomaly, sources tend to interfere with one another and consequently source edges may be impossible to detect. In this paper, we first construct an anisotropic Gauss function based on coordinate rotation, then we propose the formula of calculating anisotropy normalized variance to detect source edges, and clarify its geological significance through theoretical analysis. The numerical experiment shows the method is stable and effective. Applications to both synthetic data and aeromagnetic data in mid Yangtze region indicate that calculation of anisotropy normalized variance can effectively determine the gravity and magnetic source boundaries, especially for weak anomalies. The calculated boundaries bear high‐resolution and ample information, and will facilitate the integrated interpretation of data.