实现重磁异常规格化总梯度的傅氏积分法

IMPLEMENTATION OF THE NORMALIZED TOTAL GRADIENT OF GRAVITATIONAL-MAGNETIC ANOMALY BY FOURIER INTEGRATION

地矿部北京计算中心

别廖兹金在实现重力规格化总梯度时采用了傅氏级数求和法。为了提高运算速度及计算精度,本文应用快速傅氏变换的计算机算法将规格化总梯度法作了改进,其中将原方法选取不同谐波数对应为选取不同截断频率。文中从理论上证明了磁异常的规格化总梯度与磁化方向无关,故可同样地用于重力与磁异常解释。为了对比,文中提供了对于同一条重力剖面用两种方法计算的规格化总梯度结果。最后给出了应用实例。

In the implementation of the normalized total gravity gradient by Bieriozkin, the Fourier series summation technique has been adopted. In order to speed up the calculation and increase the accuracy, some improvements have been made on the normalized total gradient technique by the application of FFT algorithm on computer. One of these improvements is to alter the selection of harmonnic number into the selection of truncated frequency.It has been proved in theory that the normalized total gradient of the magnetic anomaly has nothing to do with the direction of magnetization. Hence, the method recommended can also be used in the interpretation of magnetic anomaly.For the purpose of comparison, two calculated results of the normalized total gradient have been presented. Both of them are from the same gravity profile.Some examples of the application of this method are given at the end of this paper.