煤矿采空区探测中的瞬变电磁干扰压制

煤田瞬变电磁探测常在人文干扰较强的煤矿周边进行工作,采集到的二次感应场信号大多噪声水平较高,难以开展处理解释工作.为消除野外数据中的电磁干扰,根据衰减曲线形态特征,利用曲线斜率的平均值及方差统计作为干扰判别机制,并参考邻近未受干扰的测点特性,可以快速简便地压制干扰,较好地恢复原始信号.使用该方法对理论数据与实测数据进行了处理解释,结果证明了方法的有效性.将该方法应用于煤矿采空区探测中,压制干扰后的曲线反演解释异常显示出与已知资料高度的一致性,得到了与实际相符的结果.

TEM INTERFERENCE SUPPRESSION IN EXPLORATION OF THE MINED-OUT AREA IN THE COAL MINE

Coal transient electromagnetic exploration is often conducted around a coal mine where man-made interference is stronger and noise in a secondary induction field signal-level is mostly rather high, and hence it is difficuh to carry out the work of processing and interpretation. In order to eliminate the electromagnetic interference in data, the authors used the average and variance statistics of slope as mechanisms of interference discrimination according to the morphological characteristics of the decay curve and by refering to the properties of neighboring measuring points without suffering from interference, quickly and easily suppressed the interference and restored the original signal satisfactorily. The theoretical data and measured data obtained by this method were used to make processing and interpretation, which proved the effectiveness of this method. This method was used in the detection of the mined-out area of the coal mine, the anomaly interpretation through curve inversion after interference suppression was highly consistent with the data available, and hence the result in agreement with the reality was obtained.