地震数据采集站系统延时测试方法

The Testing Method of Group Delay for Seismic Data Acquisition Station

系统延时特性是地震数据采集系统的重要性能指标,它代表实际采集的数据起始时间与时断(TB)信号之间的延迟,其准确度直接影响到地震数据处理时对地层分辨的正确性。介绍了地震数据采集站系统延时的定义,指出采集站的系统延时主要决定于其所使用的数字滤波器,针对目前在地震数据采集站中普遍使用的线性相位和最小相位两种滤波器所具有的不同的延时特性,基于模拟信号数字处理技术,提出了测试以上两种滤波器系统延时的不同方法和方案,详细推导了检测中的计算公式,并讨论了对测试用信号的要求。最后给出了实际测试的结果。

The group delay of telemetry seismic data acquisition station was a very importance performance index which should be checked in the telemetry seismic data acquisition systems,and it influenced on stratum resolution in seismic data processing directly.The basic definition of group delay of seismic data acquisition station was introduced,it is pointed out that the group delay of data acquisition stations mainly depends on digital filters used for data acquisition.According their different group delay characteristics of linear phase and minimum phase filters widely used in the telemetry seismic data acquisition station and based on analog-digital signal processing technique,different methods are proposed to test group delay for above two types of filters.It gives a useful test scheme and deduces the calculating formulae in detail,also discusses the requirements for testing signal.Finally it gives the testing results.