地震监测实时仿真对比系统在水库气枪主动源激发观测实验中的应用

Application of real-time simulation and comparison system for seismic monitoring in reservoir air gun experiment

气枪震源具有高度可重复性,可用于检测和分析地震监测仪器的响应特性。2016年5—6月,在福建漳州南一水库、永定棉花滩水库进行气枪主动源激发观测实验,使用全球导航卫星系统GNSS、强震仪、烈度计实时采集数据,应用地震监测实时仿真对比系统,将强震仪和烈度计记录信号仿真为位移信号,与GNSS记录的真实位移信号进行对比分析,验证实时仿真对比算法的可靠性、适用条件以及强震仪和烈度计记录位移的能力。结果表明,该实时仿真对比系统具备实时数据接收、数据处理、数据显示功能,实现了各类仪器记录波形的实时对比,具体如下:①GNSS仪器Trimble NetR9记录的GPS信号,与北斗信号差分解算后的精度(水平向精度5mm,垂直向精度10mm)相当;②烈度计VH-GL-LDY与强震仪CMG-50TCDE记录波形具有较好的一致性,采用同一NTP授时服务器,CMG-50TDE在授时精度上的表现优于VH-GL-LDY;③强震仪和烈度计记录的加速度信号可以仿真得到相对真实的位移时程,且仿真位移信号在10—60 s频带范围内与GNSS位移信号的相关性最高。

The air gun source is highly repeatable and can be used to detect and analyze the response characteristics of seismic monitoring instruments,so we developed a real-time simulation and comparison system for seismic monitoring and applied it in the air gun active source excitation observation experiments of Nanyi reservoir in Zhangzhou,Fujian,and Mianhuatan reservoir in Yongding from May to June 2016.The system collects real-time data of GNSS,strong motion instrument,and intensity meter simulates the signals of strong motion instrument and intensity meter as displacement signals and compares them with the displacement signals of GNSS to verify the reliability and application conditions of the real-time simulation comparison algorithm and the ability of strong earthquake instrument and intensity meter to record displacement.The results show that:①The system has three functional modules:real-time data receiving,data processing,and data display.It also realizes the real-time waveform comparison function of different instruments.The GPS and Beidou signals recorded by GNSS instrument(Trimble NetR9)have the same accuracy(5 mm in horizontal direction and 10 mm in vertical direction)after the difference solution.②The waveforms of theintensity meter(VH-GL-LDY)and strong motion meter(CMG-50TDE)have a good consistency.When the same NTP timing server is used at the same time,the CMG-50TDE instrument performs better than the VH-GL-LDY instrument in timing accuracy.③The acceleration signal recorded by the strong seismometer and intensity meter can be simulated to obtain the relatively real displacement and the simulated displacement signal has the highest correlation with the GNSS displacement signal within the frequency band of 10-60 s.