Abstract
Downward continuation is known as one of the crucial steps in interpreting gravity or magnetic data. As the continuation depth and the influence of noise increases, the results of downward continuation become unstable. Based on the computation of the Chebyshev-Padé approximation function obtained by the Tikhonov regularization, this paper proposes a new regularized method intended for the downward continuation of potential fields. The Chebyshev-Padé approximation function is applied to calculate the continuation factor. In this study, the cross-correlation method is adopted to calculate the cut-off wavenumber, while the regularized low-pass filter is designed to calculate the downward continuation of the potential field. In order to validate this method, numerical simulation is conducted. We calculate the root mean square error of the theoretical data on the target plane and the data of downward continuation, as obtained using the improved regularization operator method, the Chebyshev-Padé approximation function method, the regularized Chebyshev-Padé approximation function method, and the method proposed in this paper, based on which a comparison is conducted. According to the simulation and experimental results, the effects of the continuation depth can be reduced significantly by the proposed method. Besides, the method demonstrates strong resistance to noise.
Similar content being viewed by others
References
Abedi M., Gholami A. and Norouzi G.H., 2013. A stable downward continuation of airborne magnetic data: A case study for mineral prospectivity mapping in Central Iran. Comput. Geosci., 52, 269–280.
Chen S.C. and Xiao P F., 2007. Wavenumber domain generalized inverse algorithm for potential field downward continuation. Chinese J. Geophys.-Chinese Ed., 50, 1571–1579 (in Chinese).
Cooper G.R.J., 2019. The downward continuation of aeromagnetic data from magnetic source ensembles. Near Surf. Geophys., 17, 101–107.
Dmitriev V. and Dmitrieva I., 2012. Iterative method for analytical continuation of the gravity field. Comput. Math. Model., 23, 51–55.
Evjen H.M., 1936. The place of the vertical gradient in gravitational interpretations. Geophysics, 1, 127–136.
Fedi M. and Florio G., 2002. A stable downward continuation by using the ISVD method. Geophys. J. Int., 151, 146–156.
Gang Y. and Lin Z., 2018. An improved stable downward continuation of potential fields using a truncated Taylor series and regularized vertical derivatives method. J. Geophys. Eng., 15, 2001–2008.
Guo L.H, Meng X.H, Chen Z.X., Li S.L. and Zheng Y.M., 2013. Preferential filtering for gravity anomaly separation. Comput. Geosci., 51, 247–254.
Hansen R.O. and Miyazaki Y., 1984. Continuation of potential fields between arbitrary surfaces. Geophysics, 49, 787–795.
Hansen P.C., 1994. Regularization tools: A MatLab package for analysis and solution of discrete ill-posed problems. Numer. Algorithms, 6, 1–35.
Lawson C.L. and Hanson R.J., 1974. Solving Least Squares Problems. Prentice-Hall, Englewood Cliffs, NJ.
Li Y. and Oldenburg D.W., 2010. Rapid construction of equivalent sources using wavelets. Geophysics., 75, L51–L59.
Li Y., Devriese S.G., Krahenbuhl R.A. and Davis K., 2013. Enhancement of magnetic data by stable downward continuation for UXO application. IEEE Trans. Geosci. Remote Sens., 51, 3605–3614.
Li H., Wang G. and Bai Y., 2009. Calculus. Higher Education Press, Beijing, China (in Chinese).
Liu D.J., Hong T.Q., Jia Z.H., Li J.S., Lu S.M., Sun X.F. and Xu S.Z., 2009. Wave number domain iteration method for downward continuation of potential fields and its convergence. Chinese J. Geophys.-Chinese Ed., 52, 1599–1605 (in Chinese).
Ma G., Liu C., Huang D. and Li L., 2013. A stable iterative downward continuation of potential field data. J. Appl. Geophys., 98, 205–211.
Ma T., Wu Y., Hu X. and Wu M., 2014. One-step downward continuation of potential fields in a wavenumber domain. J. Geophys. Eng., 11, 025002.
Oliveira Jr. V.C., Barbosa V.C. and Uieda L., 2013. Polynomial equivalent layer. Geophysics., 78, G1–G13.
Pawlowski R.S., 1995. Preferential continuation for potential-field anomaly enhancement. Geophysics, 60, 390–398.
Pasteka R., Karcol R., Kušnirák D. and Mojzeš A., 2012. REGCONT: A MATLAB based program for stable downward continuation of geophysical potential fields using Tikhonov regularization. Comput. Geosci., 49, 278–289.
Ravat D., Pignatelli A., Nicolosi I. and Chiappini M., 2007. A study of spectral methods of estimating the depth to the bottom of magnetic sources from near-surface magnetic anomaly data. Geophys. J. Int., 169, 421–434.
Spector A. and Grant F.S., 1970. Statistical models for interpreting aeromagnetic data. Geophysics, 35, 293–302.
Tikhonov A.N., Glasko V.B., Litvinenko O.K. and Melikhov V.R., 1968. Analytic continuation of a potential in the direction of disturbing masses by the regularization method. Izv.-Phys. Solid. Earth, 12, 738–747.
Xu S.Z., 2006. The integral-iteration method for continuation of potential fields. Chinese J. Geophys.-Chinese Ed., 49, 1054–1060 (in Chinese).
Xu S.Z., Yang J.Y., Yang C.F., Xiao P.F., Chen S.C. and Guo Z.H., 2007. The iteration method for downward continuation of a potential field from a horizontal plane. Geophys. Prospect., 55, 883–889.
Zeng X., Li X., Su J., Liu D. and Zou H., 2013. An adaptive iterative method for downward continuation of potential-field data from a horizontal plane. Geophysics., 78, J43–J52.
Zeng X., Liu D., Li X., Chen D. and Niu C., 2014. An improved regularized downward continuation of potential field data. J. Appl. Geophys., 106, 114–118.
Zeng X., Li X., Jia W. and Liu D., 2015. A new regularization method for calculating the vertical derivatives of the potential field. Chinese J. Geophys.-Chinese Ed., 58, 1400–1410 (in Chinese).
Zhang H., Chen L.W., Ren Z.X., Wu M.P., Luo S.T. and Xu S.Z., 2009. Analysis on convergence of iteration method for potential fields downward continuation and research on robust downward continuation method. Chinese J. Geophys.-Chinese Ed., 52, 511–518 (in Chinese).
Zhang H., Ravat D. and Hu X., 2013. An improved and stable downward continuation of potential field data: The truncated Taylor series iterative downward continuation method. Geophysics, 78, J75–J86.
Zhou W., Li J. and Yuan Y., 2018. Downward continuation of potential field data based on Chebyshev-Padé approximation function. Pure Appl. Geophys., 175, 275–286.
Acknowledgements
This work was supported by the National Natural Science Foundation of China (No. 51305454).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Li, J., Zhang, Y., Fan, H. et al. A stable regularization method of downward continuation of potential field. Stud Geophys Geod 64, 391–406 (2020). https://doi.org/10.1007/s11200-019-0760-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11200-019-0760-3