分布式槽波地震数据同步采集系统设计

Design of distributed synchronous acquisition system of seam seismic data

为实现槽波地震数据采集系统中各个采集终端之间及同一采集终端2个通道之间的同步,设计了一种分布式的双通道槽波地震数据同步采集系统。该系统采用弱信号调理电路提高地震信号的信噪比,采用八通道同步采样芯片实现了同一采集终端上2个通道的同步采样,构建了由GPS接收机、数字锁相环及STM32主控制器组成的时钟同步系统,并采用自适应恒温晶振模型驯服算法对恒温晶振的温漂特性和老化特性进行预测和校准,使得各采集终端在矿井中仍可保持长期的时钟同步和时间同步。测试结果表明,该系统实现了分布式多通道地震信号的同步采集,在井下连续工作8h,各个数据采集终端之间的同步精度优于10μs。

In order to synchronize various collection terminals with each other and synchronize twochannel in the same collection terminal in acquisition system of seam seismic data,a distributed two-channel synchronous acquisition system of seam seismic data was designed.The system applies a weak signal conditioning circuit to improve signal-to-noise ratio of seismic signal, and uses eight-channel synchronization sampling core to realize synchronization sampling of two-channel in the same collection terminal.A clock synchronization system is constructed which is composed of GPS receiver,digital phase lock loop and STM32 main controller.The adaptive oscillator model drift correction algorithm is used to predict and estimate temperature-drift characteristic and aging characteristic of oven controlled crystal oscillator,so as to realize clock synchronization and time synchronization of various collection terminals in coal mines.The test results show that the system realizes distributed synchronous acquisition of multichannel seismic signal,the accuracy of synchronization between the different data collection terminals is better than 10μs within 8hours continuous work in underground coal mine.