摘要
距离陆地较远的海域因其超过陆地地磁台站有效控制范围,而投放海底地磁观测站又会出现无法获取数据的现象,使得远海海域磁测数据日变改正难度大,因此探讨如何在此情况下合理进行日变改正变得尤为重要。针对海洋磁力测量中地磁日变数据缺失的问题,分别采用回归分析法、谐波分析法和CM4模型法三种方法进行地磁日变值数值模拟,并与实际采集的日变观测数据比较,发现以谐波分析法计算结果偏差最大,回归分析法计算结果偏差最小,且三种结果偏差大值均集中在磁扰发生时段,同时三种方法的适用条件各不相同。通过研究分析可知,对于远海海域使用三种模拟方法均可获得某位置处地磁日变值,但需要根据已收集地磁台站数据情况进行模拟方法选择。
Diurnal variation correction is an important step in marine magnetic data processing;however,correcting the daily variation in the open sea area is more challenging than in the offshore sea.It will directly affect the diurnal variation correction especially when the geomagnetic observation data close to the study area cannot be obtained.We select a region in the western Pacific Ocean as the research area and compare the deviation between the data calculated by three different methods,which are regression analysis、harmonic analysis,CM4 model calculation,and the observation data from the undersea geomagnetic observation station,then we found that deviation of harmonic analysis is the largest,the deviation of regression analysis is the smallest,and the results obtained by the three methods are all concentrated in the time when the magnetic disturbance occurred;however,the application conditions of the three methods are different,the regression analysis method has the highest requirements for data.We know that for the research area,diurnal variation data at a particular location can be obtained by all three methods,but we need to select a suitable method according to the actual condition.We can provide the basis for the following work by discussing the method of diurnal variation correction,which is suitable for some regions of the Western Pacific Ocean.
作者
张向宇
ZHANG Xiangyu(Guangzhou Marine Geological Survey,China Geological Survey,Guangzhou 511458,China;National Engineering Research Center for Gas Hydrate Exploration and Development,Guangzhou 511458,China)
出处
《物探化探计算技术》
2025年第1期124-131,共8页
Computing Techniques For Geophysical and Geochemical Exploration
基金
中国地质调查局项目(DD20221912)。
关键词
海洋磁力测量
日变改正
数值模拟
谐波分析
回归分析
CM模型
marine magnetic data
diurnal variation correction
data simulation
regression analysis
harmonic analysis
CM model
