Local noise prediction filtering for central induction transient electromagnetic sounding
Local noise prediction filtering for central induction transient electromagnetic sounding
复制标题
中央感应瞬变电磁测深的局部噪声预测滤波
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
B. Spies
中科院分区：
文献类型：
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作者：
B. Spies
局部噪声预测滤波（LNPF）是一种设计用于环内瞬变电磁（TEM）勘探方法的降噪方法。LNPF基于三个正交磁场分量的同时测量和时域滤波器的计算，该时域滤波器从两个水平分量预测垂直分量。对于在水平分层的大地上进行的环内或中心感应探测，TEM信号完全包含在垂直分量内。因此，用LNPF获得的预测时间序列是预测的电磁噪声，其可以在后续处理中从测量的垂直分量中减去。对于低频噪声，该方法使用三点预测滤波器将信噪比提高约五倍。较长的滤波器提供上级性能，但计算密集。探测深度应该增加40%，因为信噪比增加了五倍。
Local noise prediction filtering (LNPF) is a method of noise reduction designed for use with the in‐loop transient electromagnetic (TEM) method of exploration. LNPF is based on simultaneous measurements of three orthogonal magnetic‐field components and the calculation of a time‐domain filter which predicts the vertical component from the two horizontal components. For in‐loop, or central induction, sounding over a horizontally layered earth, the TEM signal is contained wholly within the vertical component. Thus the predicted time series obtained with LNPF is the predicted electromagnetic noise which can be subtracted from the measured vertical component in subsequent processing. For low‐frequency noise, the method results in improvements in the signal‐to‐noise ratio of about a factor of five using a three‐point prediction filter. Longer filters give superior performance but are computationally intensive. The depth of exploration should increase by 40 percent, due to the five‐fold increase in signal‐to‐noi...