GJI Geomagnetism, rock magnetism and palaeomagnetism Estimation of magnetotelluric transfer functions in the time domain over a wide frequency band
GJI Geomagnetism, rock magnetism and palaeomagnetism Estimation of magnetotelluric transfer functions in the time domain over a wide frequency band
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GJI 地磁、岩石磁和古地磁 宽频带时域大地电磁传递函数的估计
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发表时间：
2004
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通讯作者：
K. Nowożyński
中科院分区：
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作者：
K. Nowożyński
摘要传递函数的确定是大地电磁（MT）和地磁数据处理的主要目标。在本文中，我们描述了一种新的算法，通过确定的脉冲响应在时域中找到一个传递函数。所提出的方法是针对我们通常在短周期记录中处理的长时间序列开发的。它允许确定广泛频率范围内的传递函数，唯一的限制是记录的持续时间。与其他确定时域传递函数的方法相比，我们选择了脉冲响应的近似，其中待确定的未知数的数量与对数尺度上的感兴趣的频率范围成比例。这是处理MT阻抗张量或地磁矢量等函数的自然方法。我们的近似可以很容易地找到预测的电场，这是非常有用的评估记录数据的质量。
SUMMARY Determination of the transfer function is the main objective in magnetotelluric (MT) and geomagnetic data processing. In this paper we describe a new algorithm for finding a transfer function through determination of the impulse response in the time domain. The proposed method was developed for the long time-series with which we are usually dealing in shortperiod recording. It allows the determination of the transfer function for a broad range of frequencies, the only limitation being the duration of recording. In contrast to other methods for determination of the time-domain transfer function we selected an approximation of impulse response in which the number of unknowns to be determined is proportional to the frequency range of interest on a logarithmic scale. This is a natural way to deal with functions such as the MT impedance tensor or geomagnetic vector. Our approximation makes it easy to find the predicted electric field, which is very useful for assessing the quality of the recorded data.