top-hat变换与庐枞矿集区大地电磁强干扰分离

作为一种非线性信号处理方法，基于数学形态学的广义形态滤波已经展现出其在大地电磁时间域信号去噪中的作用；然而，广义形态滤波在滤除大地电磁时间域信号中噪声波形的同时，也滤除了时间域信号中包含有用信息的缓变化。针对这一问题，提出一种基于数学形态学top-hat变换的大地电磁时间域噪声压制方案，利用top-hat变换对波峰和波谷的检测能力，采用直线型结构元素，对大地电磁时间域信号进行去噪。用该方法对庐枞矿集区大地电磁实测数据进行处理后，数据的标准差与曲线相似性参数都优于处理前数据，表明所提方法能够去除噪声波形并保留时间域信号的缓变化，恢复受噪声污染的大地电磁时间域信号，提高大地电磁视电阻率曲线的质量。

Top-Hat Transformation and Magnetotelluric Sounding Data Strong Interference Separation of Lujiang-Zongyang Ore Concentration Area

Morphology filtering based on mathematical morphology as a nonlinear signal processing method has demonstrated its value in magnetotelluric time-domain signal de-noising. But morphology filtering remove the steep-gentle changing of magnetotelluric time-domain signal which also contains useful information while remove the noise waveform of magnetotelluric time-domain signal. To solve this problem, the authors present a scheme based on top-hat transformation of mathematical morphology in noise suppression of magnetotelluric time-domain signal, using the ability of top-hat transformation on detecting peaks or troughs and flat structural elements to remove the noise from magnetotelluric time-domain signal. The results of processing measured magnetotelluric sounding data collecting from Lujiang-Zongyang ore concentration area by the proposed method show that the proposed method can remove noise waveform while reserving the steep-gentle changing of time-domain signal, restore the magnetotelluric time-domain signal contaminated by noise and improve the quality of magnetotelluric apparent resistivity curve.