全张量磁梯度数据的斜导数特征值边界识别方法研究

Oblique derivative edge detection method research on full tensor magnetic gradient data

本文提出了一种全张量磁梯度数据的斜导数边界识别方法,该方法利用全张量磁梯度数据定义了北向斜导数、东向斜导数和垂向斜导数.模型试验表明,北向和东向斜导数无法有效识别磁性异常体边界,异常形态复杂虚假异常较多,而垂向斜导数在高纬度斜磁化或者垂直磁化条件下可以清晰而准确得识别地质体的边界,具有一定的深度识别能力.与现有磁张量梯度的边界识别方法相比,识别效果好,可以有效均衡不同深度地质体的响应.将上述方法应用于大兴安岭地区实测航磁三分量数据转换得到的全张量数据,获得了研究区浅部磁性体的分布,并与三分量数据进行联合解释,取得良好的地质效果.

A oblique derivative edge detection method for full tensor magnetic gradient data is presented in this paper.This method uses full tensor magnetic gradient data to define northward oblique derivative,eastward oblique derivative and vertical oblique derivative.Model tests show that the derivatives of the north and east oblique derivatives cannot effectively determine the boundaries of magnetic anomalies,the anomaly pattern is complicated and there are many false anomalies.While the vertical derivatives can clearly and accurately determine the boundaries of geological bodies under high latitude oblique magnetization or vertical magnetization conditions.Compared with the existing edge detection methods of full tensor magnetic gradient data,the recognition effect is better,and the method can effectively balance the response of geologicalbodies with different depths.The above method is applied to the full tensor data obtained from the three-component aeromagnetic data conversion in Daxing’anling area,and the distribution of the shallow magnetic bodies in the study area is obtained.Good geological results are obtained with jointly interpretation of the three-component data.