基于Hartley变换的归一化总梯度法

归一化总梯度法对下半空间的重力总梯度模进行归一化计算,从而利用极值来获得地质体的分布,但现有计算方法存在计算精度较低的问题,并且计算结果不太稳定。本文采用Hartley变换,并引入新的余弦滤波因子,实现重力归一化总梯度,来压制高频干扰;此外,针对计算过程中下延深度越大干扰越严重的弊端,将余弦滤波因子的幂次设计为随深度变化的函数,从而获得更加稳定的计算结果。模型试验和在玲珑金矿区采空区的实际数据结果表明,所提出的重力归一化总梯度法具有计算速度快、精度高、稳定性强等优点。

Normalized Total Gradient Method Based on Hartley Transform

The normalized total gradient method is a normalized calculation of the gravity total gradient mode in the lower half space, and its extreme value is used to obtain the distribution of geological bodies. The existing calculation methods have the disadvantages of low calculation accuracy and unstable results. In this study, the Hartley transform is used to realize the normalized total gradient of gravity, and a new cosine filter factor is introduced to suppress high frequency interference. In addition, the power of the cosine filter factor is designed to overcome the serious interference of deeper calculation depth,which is a function of the depth,and leads to more stable calculation results. The model test and actual data in Linglong Goldfield show that the proposed gravity normalized total gradient method has the advantages of fast calculation, high precision and strong stability, and has a good practical application value.