The Research And Application Of Frequency Domain Filtering In Gravity Anomaly Separation

In the rapid development of the new generation,geophysical equipment to improve the accuracy and further improve the theoretical basis to promote geophysical methods are also rapid development.The selection of geophysical methods depends on the physical properties of the object and the surrounding objects,and the gravity exploration based on the density difference is one of the indispensable technologies.Gravity exploration includes data collection,processing and interpretation of three parts.The gravitational field is the superposition field,and the observed gravity anomalies are the comprehensive reflections of the various densities of the different densities below the observation point.So how do we study(local)anomalies from some geologic bodies that we study(detect)In the accurate separation is particularly important.It is necessary to make the separation of the anomaly can more accurately express the geological situation,to minimize the measurement error,reduce the instrument error on the basis of the late data analysis,processing is played a role in the interpretation of the anomaly to provide accurate Of the information,which is decided to invert the results of the premise of good or bad.From the successful development of the gravitometer in the 1930 s,nearly 100 years have elapsed.With the continuous research and study of experts and scholars in various countries,the article on the spatial domain method,including the mean field method,the circumference method and the cutting method,has been common.The method of domain filtering is less studied and applied in anomalous separation,and no comparison is made with the effect of very mature spatial domain method.In this paper,the matched filtering and Wiener filtering theory in the frequency domain filtering method are described in detail.Then,the related calculation program is written.Through the theoretical model experiment and analysis,it is proved that the frequency domain filtering(matched filtering and Wiener filtering)And the results were compared with the mean field method,the circumferential method and the cutting method in the spatial domain method.The results show that the effect of frequency domain filtering(matched filtering,Wiener filtering)separation anomalies in the same model is similar to that of the spatial domain method(mean field method,circumferential method and cutting method),and the separation effect is better than that in the vertical superposition model Spatial domain method,in terms of time is shorter than the spatial domain method.The practical significance of the frequency domain filtering in the separation anomaly is that the approximate depth information of the corresponding model(orebody)can be obtained from different spectra.The Wiener filter extracts the gravity anomalies such as the radial maximum logarithmic power spectrum,Matched filter is extracted from the gravity anomaly vertical first order derivative radial mean logarithmic spectrum),with a certain degree of adaptability.Finally,the results are applied to the separation of gravity superposition anomalies in a copper and iron ore in Sichuan,and a good effect is obtained,which proves that the method has certain practicability.