A new method for spectral analysis of the potential field and conversion of derivative of gravity_anomalies: cosine transform
重力位谱分析及重力异常导数换算新方法——余弦变换

In order to improve the accuracy of derivative conversion of gravity anomalies and reflect anomaly characteristic of geologic bodies effectively, we propose a new method of calculating anomaly derivative using cosine transform. Two theorems are put forward and proved and the common expression of the cosine transform spectrum of the gravity potential field and the formula to calculate derivatives of gravity anomalies are deduced, So the theory of cosine-transform-spectrum of the potential-field is established, In model experiments, we find that the deviation of the first derivative calculated by Fourier transform is very large to comparing with the theoretical derivative, but the fitting effect of the derivative of anomalies calculated by cosine transform is very good. The calculation accuracy of data are all very high except that errors of several data on the boundary are large because of the residual Gibbus effect induced by finite truncation of gravity anomalies. Errors are -0.09% -5%.