野外采集压制低频对原始数据质量的影响

在地震勘探野外采集中,使用高频检波器和提高仪器前置放大器的低截频,会压制地震信号的低频部分。对其造成的后果,在认识上有2种观点:一种观点认为,压制低频可以相对提高高频信号的幅度,能记录更多弱的高频信息,有利于分辨率的提高;另一种观点认为这种措施会使低频信息受到压制,影响地震资料的分辨率。通过一次野外试验的结果对这个问题进行了探讨,认为检波器—仪器前放滤波器组成的系统不会改变数据的信噪比谱和有效带宽。因此在特定的工区,只有利用经过了叠前反褶积和去噪处理的叠加剖面,才可以判断检波器的自然频率和仪器低截频值对数据质量的影响。

The effect of suppression for low frequency signals on the acquired data in the field

The adoption of high frequency receiver and higher cutoff frequency preamplifier will suppress the low frequency seismic signals in data acquisition. However, there are two viewpoints about the effect that follows. One is that it will benefit the seismic resolution by relatively promoting the amplitudes of high frequency signals. The other is that it will impair the seismic resolution due to the suppression of low frequency signals. This paper illustrated by the results of a field experiment that the combination of receiver and preamplifier would not impair the signal to noise ratio and effective bandwidth. For a particular survey area, the effect of the natural frequency of a receiver and the lower cutoff frequency of an instrument on data quality can only be judged by stack sections that were after prestack deconvolution and noise suppression.