Abstract：This paper defines a gradient ratio function of gravity and magnetic data,which is the ratio of first-order horizontal derivative to original anomaly.This function can directly obtain the location of geological body.The gradient ratio function has the relationship for different types of bodies,that is the horizontal distance of extremes equal to two times the depth of geological body.So this method can realize the depth calculation without any priori information.In order to low the interference of oblique magnetization,we use the ratio of analytic signal derivative to analytic signal for magnetic anomaly interpretation.The gradient ratio function calculates only the first-order horizontal derivative of anomaly,so it will not increase the interference of noise.In addition,we provide the average value of multiple upward continuation heights and upper-half space extreme imaging based on the gradient ratio function to get more accurate results.Theoretical model tests prove that the gradient ratio function can quickly and correctly calculate geologi-cal body depth,and have stronger anti-noise capability.We apply this proposed method to real magnetic data,and obtain the depth of geological bodies.
马国庆, 孟庆发, 李丽丽, 明彦伯. 利用重/磁场梯度比值函数计算地质体深度[J]. 石油地球物理勘探, 2019, 54(1): 229-234.
MA Guoqing, MENG Qingfa, LI Lili, MING Yanbo. Gradient ratio function of gravity and magnetic data for geological body depth calculation. Oil Geophysical Prospecting, 2019, 54(1): 229-234.
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