基于解析信号变深度成像的磁源参数估计方法

Estimating magnetic source parameter using variable depth imaging method based on analytic signal amplitude

磁源参数估计是磁法数据处理与解释的常用手段之一.本文从二维磁解析信号与场源参数关系式出发,引入一个深度比例因子,构建出了变深度成像函数(VDIF).根据成像极大值位置与场源深度和构造指数关系,建立了含深度比例因子的磁源参数计算公式.新方法具有较强的稳定性和成像分辨率,而且可以使用多个深度比例因子来获取一系列场源参数值,从而提高方法的可靠性.叠加模型试验表明,该方法能够在叠加磁异常中较准确地获取所有场源的深度和构造指数,同时在空间成像分辨率及抗噪能力上明显优于解析信号比值的DEXP法.将本文方法应用于黑龙江嫩北农场青年点的磁异常中,反演得到了5个磁源的参数信息.

Estimation of magnetic source parameters is one of the common methods for magnetic data processing and interpretation.Starting from the relationship between two-dimensional magnetic analytical signals and field source parameters,this paper introduces a depth scale factor to construct a Variable Depth Imaging Function(VDIF).According to the relationship between the imaging maximum,the depth of the field source and the construction index,the calculation formula of the magnetic source parameter with the depth scale factor was established.The new method has strong stability and imaging resolution,and can use multiple depth scale factors to obtain a series of field source parameter values,thereby improving the reliability of the method.The superposition model experiments show that this method can accurately obtain the depth and construction index of all field sources in the superimposed magnetic anomaly,and at the same time,it is significantly better than the DEXP method in terms of spatial imaging resolution and noise immunity.The proposed method is applied to the magnetic anomaly of the youth point of Nenbei Farm in Heilongjiang,and the parameter information of five magnetic sources is obtained by inversion.