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

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.