解析信号是磁法数据处理与解释的常用工具。本文从不同阶次解析信号及其垂向导数关系出发,引入深度缩放因子,构建了磁源变深度成像函数。该方法利用深度成像的极大值反映场源空间位置,利用反演深度及成像极大值估计场源构造指数。另外,...解析信号是磁法数据处理与解释的常用工具。本文从不同阶次解析信号及其垂向导数关系出发,引入深度缩放因子,构建了磁源变深度成像函数。该方法利用深度成像的极大值反映场源空间位置,利用反演深度及成像极大值估计场源构造指数。另外,结合不同深度缩放因子、不同阶次的成像结果提高方法的可靠性与适用性。模型试验及实例应用表明,相对于解析信号比值和局部波数的DEXP(depth from extreme points)方法,本文方法在使用更低阶次导数的情况下,能够获得更强的计算稳定性、更高的空间成像分辨率和更准确的场源参数反演结果。展开更多
The tilt-depth method can be used to make fast estimation of the top depth of magnetic bodies. However, it is unable to estimate bottom depths and its every inversion point only has a single solution. In order to reso...The tilt-depth method can be used to make fast estimation of the top depth of magnetic bodies. However, it is unable to estimate bottom depths and its every inversion point only has a single solution. In order to resolve such weaknesses, this paper presents an improved tilt-depth method based on the magnetic anomaly expression of vertical contact with a finite depth extent, which can simultaneously estimate top and bottom depths of magnetic bodies. In addition, multiple characteristic points are selected on the tilt angle map for joint computation to improve reliability of inversion solutions. Two- and three- dimensional model tests show that this improved tilt-depth method is effective in inverting buried depths of top and bottom bodies, and has a higher inversion precision for top depths than the conventional method. The improved method is then used to process aeromagnetic data over the Changling Fault Depression in the Songliao Basin, and inversion results of top depths are found to be more accurate for actual top depths of volcanic rocks in two nearby drilled wells than those using the conventional tilt-depth method.展开更多
文摘解析信号是磁法数据处理与解释的常用工具。本文从不同阶次解析信号及其垂向导数关系出发,引入深度缩放因子,构建了磁源变深度成像函数。该方法利用深度成像的极大值反映场源空间位置,利用反演深度及成像极大值估计场源构造指数。另外,结合不同深度缩放因子、不同阶次的成像结果提高方法的可靠性与适用性。模型试验及实例应用表明,相对于解析信号比值和局部波数的DEXP(depth from extreme points)方法,本文方法在使用更低阶次导数的情况下,能够获得更强的计算稳定性、更高的空间成像分辨率和更准确的场源参数反演结果。
基金supported by National Natural Science Foundation of China(No.41504098 and 41504054)Natural Program on Key Basic Research Project(No.2015CB453002)
文摘The tilt-depth method can be used to make fast estimation of the top depth of magnetic bodies. However, it is unable to estimate bottom depths and its every inversion point only has a single solution. In order to resolve such weaknesses, this paper presents an improved tilt-depth method based on the magnetic anomaly expression of vertical contact with a finite depth extent, which can simultaneously estimate top and bottom depths of magnetic bodies. In addition, multiple characteristic points are selected on the tilt angle map for joint computation to improve reliability of inversion solutions. Two- and three- dimensional model tests show that this improved tilt-depth method is effective in inverting buried depths of top and bottom bodies, and has a higher inversion precision for top depths than the conventional method. The improved method is then used to process aeromagnetic data over the Changling Fault Depression in the Songliao Basin, and inversion results of top depths are found to be more accurate for actual top depths of volcanic rocks in two nearby drilled wells than those using the conventional tilt-depth method.
