Estimating the Shapes of Gravity Sources through Optimized Support Vector Classifier (SVC)
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Abstract
In gravity interpretation methods, an initial guess for the approximate shape of the gravity source is necessary. In this paper, the support vector classifier (SVC) is applied for this duty by using gravity data. It is shown that using SVC leads us to estimate the approximate shapes of gravity sources more objectively. The procedure of selecting correct features is called feature selection (FS).
In this research, the proper features are selected using inter/intra class distance algorithm and also FS is optimized by increasing and decreasing the number of dimensions of features space. Then, by using the proper features, SVC is used to estimate approximate shapes of sources from the six possible shapes, including: sphere, horizontal cylinder, vertical cylinder, rectangular prism, syncline, and anticline. SVC is trained using 300 synthetic gravity profiles and tested by 60 other synthetic and some real gravity profiles (related to a well and two ore bodies), and shapes of their sources estimated properly.
Key words
gravity sources shapes SVC feature gravity profile FSReferences
- Ardestani, V.E. (2008), Modelling the karst zones in a dam site through microgravity data, Explor. Geophys. 39, 4, 204–209, DOI: 10.1071/EG08022.CrossRefGoogle Scholar
- Ardestani, V.E. (2009), Residual gravity map of a part of Institute of Geophysics of University of Tehran, University of Tehran, Tehran, Iran.Google Scholar
- Baan, M., van der, and Ch. Jutten (2000), Neural networks in geophysical applications, Geophysics 65, 4, 1032–1047, DOI: 10.1190/1.1444797.CrossRefGoogle Scholar
- Belikov, M.V. (1978), Approximating of the external potentials of bodies rotation, M.Sc. Thesis on Physical-Mathematical Science, Institute of Theoretical Astronomy of the USSR Academy of Science, Leningrad State University (translation from Russian).Google Scholar
- Blakely, J.R. (1996), Potential Theory in Gravity and Magnetic Applications, Cambridge University Press, Cambridge, 441 pp.Google Scholar
- Camacho, A.G., F.G. Montesinos, and R. Vieira (2002), A 3-D gravity inversion tool based on exploration of model possibilities, Comput. Geosci. 28, 2, 191–204, DOI: 10.1016/S0098-3004(01)00039-5.CrossRefGoogle Scholar
- Duin, R.P.W., P. Juszczak, P. Paclik, E. Pekalska, D. de Ridder, D.M.J. Tax, and S. Verzakov (2007), PRTools4. 1–A Matlab toolbox for pattern recognition, Delft University of Technology, Delft, Netherlands, http://www.prtools.org/.Google Scholar
- Gret, A.A., and E.E. Klingele (1998), Application of Artificial Neural Networks for Gravity Interpretation in Two Dimensions, Institute of Geodesy and Photo-grammetry, Swiss Federal Institute of Technology, Zürich, Switzerland.Google Scholar
- Hashemi, H. (2010), Logical considerations in applying pattern recognition techniques on seismic data: Precise ruling, realistic solutions, CSEG Recorder 35, 4, 47–50.Google Scholar
- Hashemi, H., D.M.J. Tax, R.P.W. Duin, A. Javaherian, and P. de Groot (2008), Gas chimney detection based on improving the performance of combined multilayer perceptron and support vector classifier, Nonlin. Process. Geophys. 15, 6, 863–871, DOI: 10.5194/npg-15-863-2008.CrossRefGoogle Scholar
- Heijden, F., van der, R.P.W. Duin, D. de Ridder, and D.M.J. Tax (2004), Classification, Parameter Estimation and State Estimation, An Engineering Approach using Mathlab, John Wiley & Sons Ltd, Chichester.CrossRefGoogle Scholar
- Hekmatian, M.E., V.E. Ardestani, M.A. Riahi, A.M. Koucheh Bagh, and J. Amini (2013), Fault depth estimation using support vector classifier and features selection, Appl. Geophys. 10, 1, 88–96, DOI: 10.1007/s11770-013-0371-7.CrossRefGoogle Scholar
- Osman, O., A.M. Albora, and O.N. Ucan (2006), A new approach for residual gravity anomaly profile interpretations: Forced Neural Network (FNN), Ann. Geophys. 49, 6, 1201–1208.Google Scholar
- Plouff, D. (1976), Gravity and magnetic fields of polygonal prisms and application to magnetic terrain corrections, Geophysics 41, 4, 727–741, DOI: 10.1190/1.1440645.CrossRefGoogle Scholar
- Talwani, M., J.L. Worzel, and M. Landisman (1959), Rapid gravity computations for two-dimensional bodies with application to the Mendocino submarine fracture zone, J. Geophys. Res. 64, 1, 49–59, DOI: 10.1029/ JZ064i001p 00049.CrossRefGoogle Scholar
- Telford, W.M., L.P. Geldart, R.E. Sheriff, and D.A. Keys (1976), Applied Geophysics, Cambridge University Press, Cambridge.Google Scholar