【摘要】 为消除海磁测量中磁扰和磁暴的影响,本文提出应用维纳滤波和三次样条函数法对磁扰和磁暴日变曲线进行改正。在磁扰较小时,取几条小磁扰日变曲线经圆滑处理后作为静日变曲线,其差值作为磁扰曲线,然后取静日变曲线和磁扰曲线的平均功率谱,以此来选择维纳滤波的滤波因子;在磁暴和磁扰较大时,可多选择特征点作为样点,或根据实际经验和实际曲线定出零点和极值点作为样点,用样条函数法来分离磁暴和磁扰。理论模型试验表明,该方法优于目前使用的地方时法、小时平均法和北京时法。上述方法用于实际资料处理,取得了较好的效果。更多还原

【Abstract】 In order to remove the effects of magnetic disturbance and mag- netic storm from marine magnetic data,Wiener filtering and cubic spline function methods can be used to correct magnetic diurnal varia- tion curves with magnetic disturbance or magnetic storm.In the case of weak magnetic disturbance,first of all,N magnetic diurnal variation curves with magnetic disturbance are smoothed to get the quiet-day magnetic diurnal variation curves.Then magnetic disturbance curves can be obtained by taking the differences between the magnetic diurnal variation curves with magnetic disturbance and their corresponding qui- etday magnetic diurnal variation curves.Finally,the averaged power spectrum of quiet-day magnetic diurnal variation curves and the aver- aged spectrum of magnetic disturbance curves are respectively obtained, which are thus used to design Wiener filtering operator.When magne- tic disturbance and magnetic storm are quite strong,spline function me- thod may be used to remove magnetic disturbance and magnetic storm. In this method,characteristic points are taken as control sample po- ints;or according to observational curve,zero and extreme value poi- nts can be empirically used as sample points.The theoretical models show that these methods are superior to the currently used local time method,hour average method and Beijing time method。These methods bring quite good results in real data processing.更多还原