考虑航磁水平梯度变化的ΔT网格化方法研究

Aeromagnetic total field gridding enhancement with horizontal gradient

实测航磁横向水平梯度反映垂直于测线的磁场梯度,比传统航磁ΔT数据包含测线之间更多的磁场信息.针对航磁数据网格化问题,采用Hardwick提出的方法,利用航磁水平梯度与ΔT数据构建拟测线,并结合Akima插值法,开展了双方向测线型ΔT网格化方法研究,最终实现了考虑航磁水平梯度变化的ΔT网格化;针对网格化结果中的虚假异常采取了有效滤波方法.通过理论模型数据和实际数据网格化处理,表明该方法可以突出航磁测线之间的异常细节、更清晰地反映线性构造或磁性体走向,提高了网格化的精度和分辨率.

The measured aeromagnetic transverse horizontal gradient reflects the magnetic field gradient perpendicular to survey line and contains more magnetic field information between survey lines than magnetic total field. Based on Hardwickls method and Akima interpolation, we used aeromagnetic horizontal gradient and total field data to obtain pseudo-survey line, to carry out bidirectional line gridding study and finally realized aeromagnetic total field gridding enhancement with horizontal gradient. We also took effective filtering method to remove false anomalies in the gridding result. Theoretical models data and measured data processing results showed that this method can enhance the magnetic details between survey lines, clearly reflect the trend of linear structure or magnetic body and improve the accuracy and resolution of grid map.