经验模态分解和独立分量分解在航磁数据处理中的应用

Application of Empirical Mode Decomposition and Independent Component Analysis in aeromagnetic data processing

以东天山1∶20万航磁数据为例,利用经验模态分解(EMD)方法对航磁数据进行分解,然后利用独立分量分析(ICA)方法对分解出的固有模态函数(IMF)数据进行重构。分解出来的从高频到低频IMF与地质体的分布具有一定的相关性,不同频率的IMF代表了一定的地质意义。经过ICA重构后的独立分量(IC)能够对异常IMF函数从盲源分离的角度进行有效的重构,其结果可以在一定程度上解释不同的地质事件对磁异常的贡献,并对构造识别和构造区域划分具有一定的指示意义。

Geophysical and geochemical information obtained by field survey were multi-stages and multi-sources at present. Based on1∶ 200,000 aeromagnetic data in eastern Tianshan,and Empirical Mode Decomposition（ EMD） and Independent Component Analysis（ ICA）,the authors separated and reestablished the aeromagnetic data so as to extract the signals from different sources and reconstruct the data from Intrinsic Mode Functions（ IMF）. The distribution of EMD and geological body from high to low frequency was positively related. Independent Components（ IC） reestablished by ICA effectively indicated contribution of different geological events on the magnetic anomalies and had indicating implications for the structure identification and tectonic division.