Application Of Potential Field Separation Of Wavelet Transform In A Gravity Survey In Inner Mongolia Some Area

Gravity exploration is an important geophysical method to solve geological structure problems and mineral resources exploration.In the process of field exploration,the data we collected are superimposed anomalies produced by geological bodies with different scales,dimensions and physical properties,including abnormal bodies.In order to ensure the smooth progress of data processing and inversion in the later stage,it is necessary to separate the anomaly information containing only the target body from the superimposed anomaly.There are many kinds of potential field separation methods studied,and their advantages and disadvantages coexist,and the influence of separation parameters on the separation results is not clear.therefore,potential field separation is still a difficult problem that has not been well solved in gravity data processing and interpretation.It can accurately and quickly separate the anomalies generated by the target body from the superimposed anomalies,which not only determines the reliability of the inversion results,but also greatly improves the efficiency of data processing and interpretation.it has always been the direction of researchers to find a suitable separation method of gravity potential field.For anomalies with different field source depths and different scales,better separation results can be obtained by using conventional potential field separation methods,but for practical complex data,due to the complexity of field sources,buried depth and scale are different.in this case,the conventional Fourier transform does not contain spatial information,so it has some shortcomings such as incomplete separation and unable spatial location separation.On the basis of traditional Fourier transform,wavelet transform is developed.However,because there are many basis functions of wavelet transform and the number of layers of multi-scale decomposition is not fixed,it is necessary to establish a model similar to the geological conditions of the study area,separate and try to calculate the forward data of the model,and through the analysis of the separation results,find the optimal wavelet basis function and the number of decomposition layers.In this paper,based on the detailed introduction and analysis of several commonly used potential field separation techniques and wavelet transform multi-scale analysis techniques,through the construction of different geological models,by comparing the effects of different separation techniques,it is found that the wavelet transform multi-scale analysis technology achieves better separation results than other methods.In the process of wavelet multi-scale separation,different types of geological models using different wavelet basisfunctions and decomposition layers will achieve different decomposition results,so it is necessary to strictly guard against the phenomenon of decomposing the background field into local anomalies caused by the excessive number of wavelet decomposition layers.Finally,through the regional anomaly separation of the measured gravity data in Inner Mongolia,the effectiveness of the gravity anomaly separation method based on wavelet transform is further verified.