A new stabilizing functional to enhance the sharp boundary in potential field regularized inversion

• We propose a new stabilizing functional.
• It can highlight large property and reduce the small property.
• It changed immediately when the model parameter changed.
• It can avoid the selection of a focusing factor.

Based on geophysical regularization theory, different stabilizing functionals, such as minimum model, maximum smoothness, minimum support (MS), exponential model functional and minimum gradient support (MGS), were widely applied in geophysical inversion to obtain a stable solution. Comparing with the smooth inversion results, the focusing stabilizing functionals including MS and MGS can generate inversion results with a sharp boundary. However, focusing factors in MS (or MGS) will seriously affect the results, though there exits related method to choose an optimal focusing factor. Meanwhile the choose of a suitable focusing factor and the calculation of the model gradient in MGS may lead to a more complex inversion procedure. Therefore, based on the exponential varying property of the inversed model parameters, we propose a new stabilizing functional that not only can generate a focused inversion image but also avoid the process of selecting the focusing factor and calculation of the model gradient. We apply the new stabilizing functional to invert the gravity and magnetic anomalies, the results of model tests and case study show that it is effective in enhancing the sharp boundary.