基于磁异常ΔT计算投影分量ΔTPro的迭代算法  

An iterative algorithm for calculating component ΔT from magnetic anomaly ΔT

作　　者：胡正旺[1,2] 杜劲松 孙石达[4] 陈超 HU Zhengwang;DU Jinsong;SUN Shida;CHEN Chao(Institute of Geophysics and Geomatics,China University of Geosciences(Wuhan),Wuhan,Hubei 430074,China;Hubei Subsurface Multi-scale Imaging Key Laboratory,Wuhan,Hubei 430074,China;State Key Laboratory of Geological Processes and Mineral Resources,Wuhan,Hubei 430074,China;College of Exploration Technology and Engineering,Hebei GEO University,Shijiazhuang,Hebei 050031,China)

机构地区：[1]中国地质大学(武汉)地球物理与空间信息学院,湖北武汉430074 [2]地球内部多尺度成像湖北省重点实验室,湖北武汉430074 [3]地质过程与矿产资源国家重点实验室,湖北武汉43007 [4]河北地质大学勘查技术与工程学院,河北石家庄050031

出　　处：《石油地球物理勘探》2021年第3期645-658,I0015,I0016,共16页Oil Geophysical Prospecting

基　　金：国家自然科学基金项目“基于球坐标构建大陆岩石圈三维磁性结构的方法研究”(41604060);国家重点研发计划“深海关键技术与装备”之重点专项“深水油气近海底重磁高精度探测关键技术”(2016YFC0303000);地质过程与矿产资源国家重点实验室自主研究课题“中央造山带岩石圈结构与地球动力学研究”(MSFGPMR01-4)联合资助。

摘　　要：总磁场强度异常(ΔT)与磁场矢量异常(Ta)在主磁场(T0)方向的投影分量(ΔTPro)之间存在差异,在高磁环境下该差异更显著。为了计算方便,传统算法均将ΔT近似为ΔTPro,这可能会导致定量解释偏离实际情况。为此,提出一种基于ΔT的ΔTPro高效迭代算法。该算法采用ΔT近似为ΔTPro的理论误差公式,将实测ΔT数据代入公式,通过多次迭代得到高精度的ΔTPro。首先通过模型试验,分析了该迭代算法的有效性、收敛速度与计算精度的影响因素以及计算效率;然后,通过实际数据应用,讨论了运用该算法需要注意的相关问题,分析了该算法与传统方法之间的差异。模型试验与实际应用均表明了该方法的可靠性与稳定性;与传统方法相比,该算法所需的计算量与计算机存储量均较小,因而具有较高的计算效率和较强的实用性,值得在实际应用中推广。Total magnetic intensity anomaly (ΔT) is intrinsically different from the projected component (ΔPro) of the magnetic vector anomaly(Ta)on the direction of the main field(T0),and this difference is very obvious in a highly magnetic environment.Traditionally,to simplify computation,ΔT is always treated as ΔTPro approximately.This may cause a large error in quantitative interpretation.This paper proposes an efficiently iterative algorithm for fast calculating ΔTPro from ΔT by utilizing the theoretical difference formula between ΔT and ΔTPro.First,the factors influencing the validity,convergence rate and calculating accuracy,and computational efficiency are analyzed successively by serial model tests.Then using field data,related problems which need to be paid attention and the difference between the results from our method and a traditional method are discussed.Both model and field applications have verified the reliability and stability of our method.Furthermore,compared with other methods,our method requires a little amount of computation and computer memory.It is effective and practical,and worth being promoted in the field application.

关 键 词：总磁场强度异常 磁异常数据处理 磁场分量转换 迭代算法 高磁环境 

分 类 号：P631[天文地球—地质矿产勘探]