可控震源符号位地震记录的真振幅恢复

TRUE AMPLITUDE RECOVERY FOR SIGN-BIT SEISMIC RECORD GENERATED BY VIBROSEIS

地质矿产部石油物探研究所,南京210014

Research Institute of Geophyical Prospecting for Petroleum, MGMR, Nanjing 210014

基于伪噪声假说,可控震源符号位地震记录只需通过相关、叠加等步骤,其结果即可显示信号的相对振幅.它既不要求预先知道环境噪声的分布形式,也不要求信号一噪声(随机环境噪声)比S/N<1,而且叠加结果也不再需要作非线性校正.至于信号的恢复效果,则由信号一伪噪声比及是否有足够的叠加(含相关)次数决定.在野外数据采集过程中,不仅需要正确合宜地选取观测系统,而且还必恰到好处地选取扫描参数,以尽可能抑制伪噪声、提高信号一伪噪声比,从而降低恢复真振幅所需的叠加次数,使真振幅恢复得以实现.

The output of operations such as correlation, stacking, etc., for sign-bit seismic records generated by vibroscis, can reflect relative amplitude of the records according to pseudo-noise theory. It is not necessary neither ambient noise distribution to be known in advance, nor signal-to-noisc (random ambient noise) ratio S/N<l to be required, and nor nonlinear correction for stacked signals to be needed.As far as recovery quality of the signals is concerned, it is determined by both signal-to-pscudo-noise ratio and stacking (correlation) fold. During field acquisition, it is required not only to correctly select layout, but also to pick up suitable sweeping parameters to suppress pscudo-noise and improve signal-to-pscudo-noise ratio as possible as they can. Thus the stacking fold required by true amplitude recovery can be reduced and true amplitude recovery can therefore be realized.