基于组合滤波的矿集区大地电磁信号去噪

针对矿集区大地电磁(MT)信号受环境噪声和人文噪声污染严重的问题,提出一种结合了经验模态分解(EMD)和数学形态学滤波的组合滤波方法,对矿集区大地电磁信号的时域信号进行滤波处理。介绍了方法原理和计算步骤,评估了该方法的去噪效果;在与小波变换去噪效果对比的基础上,用仿真实验验证了方法的可靠性,并对某矿集区的实测数据进行了去噪处理。结果表明,组合滤波方法充分利用了EMD多尺度分解及其可重构特性和数学形态学滤波方法的优点,在滤除噪声的同时为MT信号尽可能多地保留了有用信息。去噪后,估算的响应曲线方差减小到原来的一半,为进一步正确资料处理和地质解释提供了保障。

De-Noising of Magnetotelluric Signal in the Ore Concentration Area Based on Combination Filter

Aiming at the problem that the magnetotelluric signal in the ore concentration is affected by the environmental noise and the human noise pollution, a combinatorial method based on the EMD and mathematical morphology filter is described for filtering of MT time-series.The principle and steps of the method are given, and the de-noising effect of this method is evaluated.Comparing with wavelet transform, the simulation test results proved the reliability of this method, and the field measurement data of a certain mine area is processed.The results show that the combined filtering method makes full use of the multi-scale decomposition and reconfigurable characteristic of EMD and the advantages of mathematical morphology filter.While filtering out the noise, the useful information is retained as much as possible for the MT signal.After de-noising, the variance of the response curve is reduced to 1/2, which provides a guarantee for the correct data processing and geological interpretation.