No abstract

Reduction of aeromagnetic noise and extraction of mineralization-related residual anomalies are critical for aeromagnetic data processing in mineral exploration. This study introduced a multifractal singular value decomposition (MSVD) method to remove the noise and improved the bi-dimensional empirical mode decomposition (BEMD) algorithm to extract residual magnetic anomalies. It is shown that MSVD and improved BEMD could effectively reduce the noise and extract residual magnetic anomalies. Then, a wavenumber–domain iterative approach is applied in 3D imaging of magnetic anomalies and gradients with depth constraints, which is a rapid tool for qualitative and quantitative interpretation of magnetic data and is suitable for rapidly imaging large-scale data. The 3D inversion result is verified by four geological sections along the regional tectonic directions and some drilling holes on the deposits. It is revealed that this proposed approach is practical and effective in dealing with aeromagnetic data interpretation and inversion for mineral exploration.

The aeromagnetic signal often has a minority of noise in it, which may be composed of random noise caused by the aircraft itself, fringe pattern noise caused by the differences between the aircraft airlines, or linear features aligned along the declination direction after reduction to the pole, which are usually hard to distinguish visually but will make useful information submerged In this paper, the aeromagnetic data of a polymetallic deposit-accumulated area in Inner Mongolia Province, northwest China, is taken as an example, from which the aeromagnetic noise is extracted by multifractal singular value decomposition (MSVD), the singular values are automatically fitted into limited number of fractal straight lines according to their inflection points and minimum fitting error, each line represents a certain kind of noise or signal, the noises are chosen and removed in this way. The last two decomposed components are usually a band pass and a low pass filter that can be used for tectonic faults and geological bodies’ interpretation, respectively.