郭为,唐新功,盛冠群. 2022. 基于最高频相位法和空间滤波法的二维模型的大地电磁静态校正. 地震学报,44(2):302−315. doi: 10.11939/jass.20210139
引用本文: 郭为,唐新功,盛冠群. 2022. 基于最高频相位法和空间滤波法的二维模型的大地电磁静态校正. 地震学报,44(2):302−315. doi: 10.11939/jass.20210139
Guo W,Tang X G,Sheng G Q. 2022. Magnetotelluric static correction of two-dimensional model based on the highest frequency phase method and spatial filtering method. Acta Seismologica Sinica44(2):302−315. doi: 10.11939/jass.20210139
Citation: Guo W,Tang X G,Sheng G Q. 2022. Magnetotelluric static correction of two-dimensional model based on the highest frequency phase method and spatial filtering method. Acta Seismologica Sinica44(2):302−315. doi: 10.11939/jass.20210139

基于最高频相位法和空间滤波法的二维模型的大地电磁静态校正

Magnetotelluric static correction of two-dimensional model based on the highest frequency phase method and spatial filtering method

  • 摘要: 静态效应一直是影响大地电磁测深法精确性的主要原因之一。在相位校正法的基础上提出了一种更适用于电性变化较为平缓的地质情况的静态校正方法—最高频相位法,其核心是用需要校正测点两侧受静态效应影响较小测点的最高频视电阻率的算术平均值代替相位法递推公式中每个频点前一个频点的视电阻率值,以消除相位法中的误差积累。以二维模型的正反演为例,通过对比空间滤波法、相位法和最高频相位法对不同模型静态校正前后的正反演结果,证明了最高频相位法的有效性和优越性,同时表明,对于电阻率变化大并且静态位移严重的水平层状地层模型,采用与空间滤波法相结合的联合校正效果更佳。

     

    Abstract: Static effect is one of the main reasons for affecting the accuracy of magnetotelluric sounding. In this paper, a static correction method, the highest frequency phase method, is proposed on the basis of the phase correction method, which is more suitable for geological conditions with smooth electrical changes. Its principle is to eliminate the error accumulation in the phase correction method by replacing the apparent resistivity value of the previous frequency point in the recurrence formula with the arithmetic mean of the highest frequency apparent resistivity of the measuring points on both sides of the measuring points that need to be corrected and are less affected by the static effect. Taking the forward and inversion of two-dimensional model as an example, the effectiveness and superiority of the highest frequency phase method are proved by comparing the forward and inversion results from spatial filtering method, phase correction method and highest frequency phase method before and after static correction for different models. It also shows that for the horizontal layered formation model with sharp resistivity difference and severe static shift, the static correction effect of joint correction which combines highest frequency phase method with spatial filtering method is much better.

     

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