磁张量梯度数据方向解析信号比值的边界识别和空间位置反演方法

磁张量梯度测量具有高分辨率、多参量的优点，能更准确地描述磁源体的分布特征，在矿产资源勘探中具有广阔的用途.磁异常解析信号具有受倾斜磁化干扰小的特点，且为了增强深部地质体的分辨能力，本文提出磁张量梯度数据的解析信号比值的均衡边界识别及空间位置反演技术.磁张量梯度数据的均衡边界识别方法为不同方向解析信号比值的反正切函数，在降低倾斜磁化干扰的同时能有效地均衡不同深度地质体的响应，提高了对较深地质体的分辨率；空间位置反演技术是建立解析信号比值与地质体位置参数的对应方程，利用解析信号比值与地质体的对应关系作为约束条件来反演获得地质体的水平位置和深度信息，具有无需已知任何先验信息的优势.通过磁性体张量异常试验表明解析信号比值的边界识别方法能清晰和准确地获得不同深度地质体的边界，所建立的反演方程能准确地计算出地质体的范围和深度，具有较高的水平分辨率和精度.将本文方法应用于实测磁张量梯度数据的解释，获得了地下铁矿的分布特征，为区域矿产资源潜力评价提供了翔实的基础资料.

Edge detection and space location inversion techniques of magnetic tensor gradient data based on ratio of analytic signal

Magnetic tensor gradient data has the advantages of high precision, high resolution, multiple parameters, which can delineate the distribution of magnetic sources more correctly, and has a wide range of uses in the exploration of mineral resources. Magnetic tensor data is still affected by the oblique magnetization that will cause the irregular distribution of anomalies, which bring difficulties to the data interpretation. Based on the advantages that the analytic signal is insensitive to magnetization direction and the goal of enhancement of deep sources, we presented balanced edge detection and space location inversion technique of analytic signal ratio to interpret magnetic tensor gradient data. The balanced edge detection method of magnetic tensor gradient data is the arc tangent function of the ratio of different directions of analytic signals, which can balance the amplitude of the sources with different depths, and can low the interference of oblique magnetization and improve the resolution to deep source. Space location inversion technique is to build the linear equation between the ratio of analytic signals and location parameters of geological bodies, and use the fractal corresponding feature between analytic signal ratio and geological body as selection criteria to obtain accurate horizontal location and depth. Modelling tests show that analytic signal ratio method of magnetic gradient tensor data can obtain the edges of the sources with different depths simultaneously, and reduce the change caused by the oblique magnetization. The linear equation of analytic signal ratio function can compute the range and depth of the source correctly, and has higher resolution and precision. We apply the new method to real aeromagnetic tensor data, and obtain the distribution of iron mineral resources, which have important sense to the evaluation of regional mineral resources.