SDZ-120型数字地震仪的前置滤波及剖面处理

Prefiltering in SDZ-120 digital seismograph and the seismic section processing,

在三维地震勘探中,我们采用两台SDZ-120型数字地震仪联机进行数据采集,由于使用前置放大器的低截止滤波器组件不同,导致了不同的滤波结果,从而使两台仪器采集同样的资料出现了相位差。使用两台DFS-V型仪器并联同步采集,也会出现这种现象。但是,这种现象比较容易识别。而在同一地区不同地震队采用这两种型号仪器采集出现这一现象,就不易识别了。因此在地震采集时,要力求采用相同的低截止滤波组件。若实际情况不允许,如果使用不同的低截止滤波组件,在数据处理时一定要对不同的滤波结果采用各自的整形子波进行处理,才能获得统一的结果,提供正确的解释,否则会导致错误的地质结论。

Joint data acquisition of two SDZ-120 digital seismographs is often used in three-dimensional seismic exploration. Different low-cut filter modules in preamplifiers bring different filtering results, so 'hat there are phase differences between the same seismic data collected by the two seismographs respectively. Similar phase difference phenomenon also occurs when two DFS-V seismographs operate simultaneously and jointly. It is easy to find the phase difference phenome- non in above cases. However, the phase difference phenomenon can hardly be found when different seismic crews use respectively the same seismographs, as mentioned above,in an exploration area. It is necessary, therefore, to use same low-cut filter modules in seismic data acquisition in an exploration area. If different low-cut filter modules are used in same data acquisition,differently-filtered seismic data must need their own shaped wavelets in data processing, so that phase-unified seismic sections can be obtained in an exploration area, resulting in good seismic interpretation. If not so, we only can obtain wrong geological result.