柴达木盆地航磁资料微弱信息增强技术研究及在线性构造识别中的应用

Research on enhancing weak signal technology and recognition of linear structures using aerial-magnetic data in the Qaidam Basin

目的利用重磁异常数据微弱信息增强技术识别线性构造的方法,并介绍其实现过程.方法文中提出了一种梯级带滤波增强非线性滤波技术与Tilt梯度及其水平导数的有效结合,增强放大微弱信息再识别提取线性构造,利用数字图象显示技术成图.结果识别出柴达木盆地线性构造多条,分析对比柴达木盆地区域地质构造资料及重力解释成果,具有较好的吻合性.为深入研究该地区线性构造、成矿特征、寻找勘探靶区补充了新的证据.结论该方法提取了区域航磁异常资料中的微弱信息,弥补传统方法的不足,对断层边界及异常的边界划定更为准确.梯级带滤波增强技术与Tilt梯度及其水平导数相结合取得良好的解释效果.

Aim A new method of recognition of linear structures using usual aerial magnetic data is introduced, and the actualization of this technology is also accounted for in this paper. The enchancing less stronger signal technology and methods of Tilt derivative and the total horizontal derivative are adopted to extract faint information, and digital image display technique is used to show the results. First, the aerial-magnetic data is computed using nonlinear filter technology to enchance the weak signal. Second, the Tilt derivative and the total horizontal derivative of each point in the region are calculated, according to the algorithm in this paper. Finally,the linear structures are recognized accord- ing to these images. The structures are then defined comprehensively combining the regional geology. A comparison and analysis between the digital image of aerial-magnetic anomalies from the Qaidam Basin and regional geological structures replenish new evidence for deep research of this region＇s structure. The recognized linear structures in the Qaidam Basin are consistent with the existing geology data. The magnetic data can be shown in an image by this method, describing more clearly than the routine methods , particularly advantaged to analyze linear structures, and the faint information can be explained from the unusual data of the region at the same time. Through the enehaneing weak signal technology and methods of Tilt derivative and the total horizontal derivative combined with the digital image technology, a good explanation effect is achieved, which can be used in the tectonic interpretation of magnetic and gravity anomalies.