频率域的快速傅立叶变换法是由航磁总场转换梯度分量和梯度分量之间相互转换的常用方法.但是,利用实测数据资料对方法的应用效果进行分析的研究较少,尤其是梯度分量之间的转换,主要是由于同时观测水平及垂直梯度的三轴向梯度测量技术刚刚起步,可利用的相关数据资料较少.本文首先利用模型研究了转换方法的特点,在此基础上重点对实例的转换结果进行分析.我们进行了总场转换梯度和水平梯度与垂直梯度间的相互转换计算,并将两组转换结果与实测梯度进行了详细的对比和分析.该实例的转换结果表明,总体来看利用总场转换的梯度,和梯度分量之间相互转换的结果都与实测梯度数据具有较好的对应关系,但相比而言,梯度之间的转换结果与实测数据吻合的更好.转换结果与实测数据的良好一致性,证明了转换方法的有效性,同时也验证了各测量参量的可靠性.
Fast Fourier transform technique is widely applied to calculating gradients from total magnetic anomalies and transformating between horizontal and vertical gradients. However, there is little case study for testing the effectiveness of the method, especially for transformation between gradients, because triaxial gradiometer systems which can measure horizontal and vertical gradients simultaneously only developed in recent years. In this paper, the model is used to study the computer accuracy and characteristics of the method, and the emphases is placed on processing and analyzing real data. Real case transformation results indicate that anomaly shapes and amplitudes are very similar in the calculated gradients and measured gradients, but it is worth noting that the calculated results from measured gradients are better than those from total magnetic anomalies. The good consistency between transformation results and measured gradients not only demonstrates the effectiveness of the method but also the reliability of measured data.