基于等效Q值的反Q滤波影响因素分析

Influence factors analysis of inverse Q filtering based on the effective Q

为了考察基于等效Q值的反Q滤波方法补偿效果的影响因素,从信噪比、等效Q值精度、调谐频率和门限阈值等方面进行研究.结果表明:信噪比越低,稳定性问题越难控制,补偿效果越不好.等效Q值选取偏小,将导致补偿过大;等效Q值选取偏大,将导致补偿不足.选择最高截止频率比选择峰值频率的频散校正效果好,地震波走时更加准确.门限阈值越大,振幅补偿越大,补偿后的振幅越接近无黏性吸收时的振幅,但将增加算法的不稳定.该研究可为在实际资料处理中正确使用反Q滤波技术提供指导.

In order to improve the compensation effect of inverse Q filtering based on the effective Q,the influence factors of this algorithm such as signal-noise ratio,precision of effective Q,the gain limit,tune frequency are analyzed.The research results show that the lower signal-to-noise ratio is,the harder stability controlling is and the worse the compensation effect is.If selected effective Q is relatively small,it can result in over-compensation.If selected effective quality factor is relatively large,it can result in under-compensation.Selected the highest cut-off frequency has better phase correction effect than peak frequency,thus the travel time is more accurate.The larger the gain limit is,the greater the amplitude compensation is and the compensation effect closer to the situation without viscosity absorption.But it can result in the algorithm unstable.These searches can provide beneficial guide to use inverse Q filtering correctly in actual data processing.