【摘要】 针对矿集区大地电磁强干扰的特征,构建组合广义形态滤波器,从时间域波形上探讨组合广义形态滤波对实测大地电磁强干扰的噪声压制效果。给出基于组合广义形态滤波的大地电磁资料处理流程,在人烟稀少、基本无电磁干扰的青海柴达木盆地进行试验研究,对包含比较单一的人工广域电磁干扰源的试验点进行组合广义形态滤波处理,横向对比时间域波形和视电阻率-相位曲线的改善情况。研究结果表明:该方法可以更加精确地勾勒出大尺度强干扰的轮廓特征,视电阻率-相位曲线的整体形态更加光滑、平稳,数据质量得到明显改善;由于该算法能有效提取暂态信号中的奇异信号,且只需进行加、减和比较运算,计算速度快,这对于在矿集区开展大地电磁强干扰的压制及资料处理具有一定应用价值。更多还原

【Abstract】 Considering the characteristics of magnetotelluric strong interference in ore concentration area, the combined generalized morphological filter was conducted, and the noise suppression effect of measured magnetotelluric strong interference was discussed by combined generalized morphological filter from time domain waveform. The magnetotelluric data processing procedure was presented based on the combined generalized morphological filter, and the relevant experimental research was carried out in sparsely populated, Qaidam Basin in Qinghai Province, where there is almost no electromagnetic interference. Using the combined generalized morphological filter for processing relatively simple artificial sources of wide field electromagnetic interference test points, the improvement situations of both time domain waveform and apparent resistivity-phase curve were compared. The results show that the proposed method can more accurately present the outline characteristics of the large-scale strong interference, and apparent resistivity-phase curve of the overall morphology is more smooth and stable. Moreover, magnetotelluric data quality is significantly improved. Since the algorithm can effectively extract singular signal in the transient signal, and only needs operations of addition, subtraction and comparison, the calculation speed increases. These potential advantages for the ore concentration area to carry out magnetotelluric strong interference suppression and data processing have application value.更多还原