Automatic determination of the cut-off wavenumber for downward continuation of potential field based on fractal radial spectrum
Downward continuation is an important technique in the processing and interpretation of gravity and magnetic potential field data,and has become a research hotspot due to its inherent instability.In order to obtain the stable downward continuation result,the downward continuation in the wavenumber domain is generally accomplished by adding a low-pass filter or modifying the downward continuation factor.The cut-off wavenumber of the filter or modification factor is the key to accurate downward continuation.In this paper,based on the physical characteristics of the fractal modified radial average power spectrum,an automatic determination method for the cut-off wavenumber of the downward continuation of the potential field is proposed.The comparative experimental results of downward continuation based on theoretical gravity model and aeromagnetic measured data show that:(1)The automatic determination method proposed in this paper has clear physical meaning,and can quickly and effectively determine the cut-off wavenumber and then obtain the regularization parameters of downward continuation.(2)The regularized downward continuation result based on the proposed method is better than that of the improved derivative iterative method.
Potential fieldDownward continuationRadially averaged power spectrumCut-off wavenumberFractal
万方数据
维普
