Equivalent Source Method In Magnetic And Gravity Weak Iinformation Extraction Research And Application

For gravity and magnetic anomaly is effected by gravity and magnetic of theinhomogeneity geological body which were different scales, different shapes anddifferent buried deep. Therefore, it can reflect the shallow crust fine structureinformation and deep geological structure information. This way, gravity andmagnetic anomaly has information aliasing effect. How to separate useful informationfrom abnormal effectively become the most important and difficult work which canmake the best use of magnetic material. People has payed more attention to the fielddecomposition which has not absolutely resolved.A field of the equivalent of a field of decision inversion of uniqueness ormultiple solution, that means gravity and magnetic anomaly has many variables, someof them are formed by the combination of variables. Different rocks can have thesame physical parameters, the same order of magnitude, may cause the sameanomalies in the surface. The surface of the observation in abnormal distribution isnot all of space field value, and this makes up the multiple solution of heavy magneticanomaly. There may exists certain observation errors and calculation errors in actualgravity and magnetic anomaly, which can also causes the inversion result of multiplesolution.The equivalent of the real source is equivalent field source, geophysical fieldexists equivalent (multiple solution), and this affects the accuracy of the geophysicaldata interpretation directly. To solve the equivalent of the earth has been ourlong-term.In general data interpretation, there’s many difficulties to explain the multiplesolution. Equivalent source is using equivalent (multiple solution) to convert, thenhighlight the useful information, increase interpretation methods, and interpret thecomplex anomaly.The characteristics of the equivalent source method: All sorts of multifarious location-field were transformed into a simple positive calculation. The calculationprocess is simple and easy to unified handling. Not to lose the edge points, it canexpand properly in some conditions. It can also used in some terrain which is largelyin rise and fall. As it only matched with real field source generates field in a certainerror range, downward continuation must be limited to certain limits, that’s thelimitation of this method.Compared with the traditional sense of numerical integral method andinterpolation points to out-perform, equivalent source method is more precisely,whether from abnormal morphology or numerical. Especially in the treatment of thedownward continuation, integral interpolation method loses a border area, andnumerical integral method has larger oscillation in edge value. The two methodscannot deep more. But equivalent source method is different, as long as the source ofthe layout of equivalent deeper, more close to the center of abnormal body, better theeffect of the extension is.To explore new special treatment methods in heavy magnetic material, try toextract the geophysical weak abnormal, separate it and treat in high resolutionspecially. In view of the gravity and magnetic data processing and interpretation ofthe special demands, carry out the method and technology research. This paperchooses the equivalent source method for gravity and magnetic weak in thegeophysical information extraction for research and application.This paper expounds the heavy magnetic exception handling conversion,equivalent source method, singular value decomposition method theory, andcompared with traditional method in the theory and model of the contrast. In thisarticle, we used the magnetic dipole as equivalent sources, simulate calculate manymulti-body models. In order to improve the effects and overcome coefficient matrixsingularity,which were obtained with various location-field transformation byequivalent sources, currently accepted morbid equations of the best solution singularvalue decomposition (SVD) method, with the equivalent source for the extremely,convert between different components, derivative conversion, upward and downwardcontinuation allele field conversion processing, and compared with the theoreticalvalues, and the calculation results are analyzed and summarized simultaneously. Itsprecision is one of the highest precision and the best affection in location-fieldtransformation ways at present. It can extract the weak information in the equivalentgravity and magnetic anomaly stack.