摘要
磁异常资料在地质矿产资源勘查以及深部地质方面有着十分重要的作用。论文对以磁异常梯度为主要研究对象的多参量综合反演问题,采用图形人机交互三维正反演手段,展开多参量综合磁异常可视化建模的关键技术研究工作。研究内容之一,开展了空间任意状态规则体模型的多参量快速正演的方法研究。论文通过定义三个旋转描述角度,并结合坐标系变换、结果反变换和公式互换方法,推导了规则体在倾斜和走向任意方向情况下的△T、三分量及其梯度(共16参量)的计算公式。内容之二是关于不规则复杂地质体的梯度计算方法及计算机三维模型设计的研究。任意形状三度体使用一阶方向导数和互换关系式得出磁异常梯度参量的计算公式;设计了具有独立数据结构、角点拓扑信息和三角面剖分算法三维计算机三维地质模型。第三个内容是设计正演并行算法。该算法采用数据分割、平行处理和结果缝合等技巧,能自动检测多核工作微机上CPU的数目,将数据区域按线程个数自动分割快速处理方法。最后综合以上成果编写完成一个集磁梯度数据处理、三维地质建模和可视交互计算于一体的工作平台,方便解释人员使用人机交互最优化选择法对实际磁测数据做多参量综合反演评估。论文主要成果和创新点:1)提出了倾斜规则体磁场及梯度的快速计算方法;2)设计了复杂多面体三维模型的数据结构;3)完成了基于计算域分割的磁数据处理并行算法研究;4)开发了“磁异常多参量可视化反演解释软件”,实现成果实用化。论文所做工作客观上促进了磁测数据处理方式由单参量向多参量综合解释转变,对于提高磁异常数据处理解释方法、突出实测数据解释效果以及加快软件研制具有积极推动意义。
Magnetic anomaly data are very valuable in the field of resource exploration, deep subsurface geology and geophysics research. This dissertation focused on how to improve inversion effect through magnetic gradient component associate with other parameters. It made use of some new technoledge, such as human-computer interaction and visualization. It carried out some significant research work on magnetic anomaly parameters and 3D geology modeling.One of the research points was about computation of magnetic anomalies and gradients for spatial arbitrary posture regular body. After defining three angles of slantwise shape-regular body and rotation of coordinate system, it deduced the new magnetic anomalies expressions of gradient component and other parameter for spatial arbitrary posture regular bodies. There are total 16 components in magnetic anomaly. There are some key points such as the rotation method of coordinate system,technique of inverse transform and formula of magnetic components.The second study point was about the methods of anomaly gradient forward computation and mathematical modeling for homogeneous polyhedral composed of triangle facets. On the base of magnetic field formula, it employed the theory between the transformation of magnetic field and that of their first derivative. Then it deduced the analytical expressions for gradient tensors of polygon. We designed the boundary models represented by triangle facets in order to suit the demand of the magnetic inversion. The modeling pattern was an algorithm of a simple polygon triangulation which contained independent data structure and topology organization.Then, the data domain paralleled algorithm was presented. It applied data partition, parallel running and data sewing technique. In this procedure, one smart number‘N’was produced automatically by reason of algorithm evaluating the actual core number of CPU on working machine. The data region was divided synchronously into N segments. Obviously, they need N task-threads to process each segment. Then the data sewing technique solved the problem of merging segmentation results.It is worth to utilizing fore-mentioned achievement to develop practical software. One goal software is completed. It included gradient forwarding, geology modeling and human-computer combinational inversion, and so on. The human-computer interactive method and optimization selection strategy was used in this inverse interpretation software system.The main results and innovations in this paper are shown as follow,1) This paper proposed one method of quick magnetic anomalies forward computation for slantwise shape-regular geo-body.2) The special data structure for an arbitrarily shaped 3D body was designed.3) The multi-thread parallel computation realization based on magnetic data segmentation tasks.4) One software named“Visualization System of Inversion Interpretation for Magnetic Anomalies with Multi-Parameters”is completed.In a word, this doctoral dissertation has improved magnetic method from using single parameter to utilizing multi-parameter, the working dimension from 2D to 3D. It was significant in enhancing magnetic inversion method and improving interpretation effect.