3-D inversion plays an important role in the quantitative interpretation of magnetic data. However, the commonly used space-domain 3-D inversion algorithms usually require a large number of forward modeling and inversion calculations. Hence, the inversion based on a large-scale data is usually inefficient. 3-D imaging is another significant algorithm for the qualitative and quantitative interpretation of magnetic data. This paper implements a frequency-domain iterative approach for 3-D imaging of magnetic anomalies and gradients, which can improve imaging efficiency and is suitable for rapid imaging of large-scale data. The frequency-domain forward formulae and imaging formulae of magnetic total field anomaly and magnetic gradients are derived in this paper. A depth scaling factor is added to the imaging formulae to significantly improve the depth resolution. In order to reduce the fitting error and improve the imaging accuracy, this paper adopts an iterative optimization algorithm. The effectiveness and feasibility of the presented approach were verified by the synthetic data and real data from a metallic deposit area in Xinjiang.
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