Fraser滤波的改进方法

• 作 者: 杨兴沐 甘波
• 机 构: 广西地勘大队,广西物探队,
• 出 处: 物化探计算技术
• 发表日期: 1986年01期
• 关键词: 动态范围 电磁测量 线性滤波 Fraser 发射频率 相邻点 点距 采样间距 甚低频 滤波法

甚低频电磁测量结果证明,异常信号总幅度为5度时仍有意义,但也会出现幅度超过45度的情况。这样,当把测量结果表示在工区图上画剖面曲线时有一个动态范围问题。1967年,Fraser发明了一种低通平滑算子,对消除动态范围问题、降低高达20千赫左右的发射频率所造成的地质噪音显示了一定的效能。其滤波算子为: f_(2,3)=(M_4+M_3)-(M_2+M_1) M_1、M_2、M_3、M_4为任意四个相邻点的测值。

Very low frequency electromagnetic measurements show that the total amplitude of the anomaly signal is still significant at 5 degrees, but there will be more than 45 degrees amplitude. In this way, there is a dynamic range problem when the measurement results indicate that the profile curves are plotted on the work area map. In 1967, Fraser invented a low-pass smoothing operator that showed some efficiency in eliminating the dynamic range problem and reducing the geo-noise caused by transmitting frequencies up to about 20 kHz. The filter operator is: f_ (2,3) = (M_4 + M_3) - (M_2 + M_1) M_1, M_2, M_3, M_4 are the measured values ​​of any four adjacent points.