曲面上航磁异常与梯度分量的转换方法

针对现有的主要以等效源法实现的曲面航磁异常转换方法存在计算工作量大,很难应用于实际中大面积航磁数据的转换处理,提出插值 迭代法和频率域转换方法相结合,实现曲面上航磁异常和梯度分量以及梯度分量之间的快速转换方法.该方法利用插值 迭代法将曲面上的航磁异常或梯度异常向上延拓到某一个平面，在该平面上利用频率域方法实现相应的转换,将转换结果延拓回原来的曲面上.模型试验结果表明,该方法具有较高的计算精度.实测数据的转换结果与实测的梯度之间具有很好的一致性,证明了方法的有效性.

Transformation of total magnetic field anomaly and gradients on irregular surface

The major problem of existing equivalent source methods commonly used for magnetic field anomaly transformation on irregular surface is time-consuming. It is difficult to apply these approaches to large data set of aeromagnetic survey. In this paper an efficient technique was proposed for calculating gradients from total magnetic field anomaly and transformation between horizontal and vertical gradient on irregular surface. This technique integrates interpolation iteration method with potential field transformation method in frequency domain, and it has high computation speed. The procedure consists of three steps. Firstly, upward continue the magnetic anomaly or gradients data to a flat level. Secondly, complete transformations by frequency domain method on this plane. At last, downward continue the calculated results to the topography surface. The model test results indicate that the method has good accuracy. Applying the method to real case indicates that there are good matches between transformation results and measured gradients. The validity of the technique is demonstrated.