基于Laplace法的磁性球体参数确定  

The parameters determination of magnetic spherical object based on Laplace approach

作　　者：卞光浪[1,2] 翟国君 刘雁春[1] 黄谟涛 

机构地区：[1]海军大连舰艇学院海测工程系,大连116018 [2]海军海弹测绘研究所,天津300061

出　　处：《地球物理学报》2011年第3期787-792,共6页Chinese Journal of Geophysics

基　　金：国家自然科学基金(40671161)资助

摘　　要：解析信号法被广泛应用于磁性目标平面位置确定中,然而,数值计算表明:斜磁化情况下,解析信号模极大值与磁性目标中心平面位置之间存在较大的偏差,最大可达探测深度的30%,从而制约了该方法在航空磁测或水深较深区域的应用.从理论上推导了磁性球体磁异常经拉普拉斯算子运算后信号(简称"拉普拉斯信号")表达式,分析了其具有的物理性质,在此基础上,提出采用Laplace法确定磁性目标中心平面位置,当地磁场与磁化强度倾角相同且大于30°时,仿真计算的磁性球体平面位置误差小于深度的4.3%,大大提高了平面位置的计算精度.此外,还给出了磁性目标的深度和磁性参数的计算方法.仿真结果表明,当磁性球体空间位置确定较为准确时,计算出的磁性球体空间位置与磁性参数和实际值较为相符.Analytic signal approach is widely applied in obtaining source locations through the maxima of the amplitude of the analytic signal （AAS）. However, the maximum value of the AAS for a sphere model does not coincide with the object epicenter exactly. The error in the horizontal location increases with the object depth, reaching a maximum of 30% of the depth. Thus, the approach is not suitable for the condition of airborne detection or deep depth. The Laplacian signal expression of magnetic sphere magnetic anomaly was deduced theoretically. Based on its characteristic, Laplace approach is proposed to locate the magnetic object, and its horizontal location error calculated by simulation is less than 4.3 %fro of the depth when the inclination is more than 30%, having the evident advantage over AAS approach. The depth and magnetism parameters calculating methods have also been brought forward, and simulation example indicates that calculated result and real value matches perfectly if exact spatial position is known.

关 键 词：磁性目标探测 Laplace法 解析信号法 球体模型 

分 类 号：P318[天文地球—固体地球物理学] P738[天文地球—地球物理学]