摘要
为实现分布式微震采集系统中各个采集终端之间以及同一采集终端多个通道之间的同步,设计了一种分布式多通道同步微震信号采集系统。利用ADS1278解决了同一采集终端多通道之间的同步采集问题,同时使用GPS时钟同步的方法解决了不同采集终端间的同步问题,在GPS设计中提出了时钟分相算法测量1 pps信号和本地秒脉冲时间误差,通过PID算法计算得到恒温晶振的频率偏差控制量来调整恒温晶振,最终使1 pps信号和本地秒脉冲信号高精度同步,从而实现不同终端之间的采样时钟同步。实验结果表明,不同数据采集终端之间的同步精度优于500 ns,实现了分布式多通道同步信号采集。
In order to synchronize various collection terminals with each other and synchronize multiple channels in the same collection terminal in the distributed seismic acquisition system, a distributed multi-channel synchronous seismic acquisition systen, is designed. The synchronization problem between multiple channels in the same colleetion terminal ean be solved by ADS1278. The same problem between different collection terminals is solved using GPS synchronous cloek. In the design of GPS, a clock phase splitting algorithm is used to measure the time errors between 1 pps clock signal and the local second pulse. The frequency deviation of Oven Controlled Crystal Oscillators（OCXO） is obtained by the PID algorithm to adjust the OCXO frequency. Eventually 1pps signal is synchronized high precisely with the local second pulse signal. Thus the sampling clock synchronization between different terminals is realized. The experimental results show that the accuracy of synchronization between the different data collection terminals is better than 500 ns, and the distributed multi-channel synchronous signal acquisition is realized.
出处
《电视技术》
北大核心
2015年第23期35-39,共5页
Video Engineering
基金
国家自然科学基金项目(61362020)
广西自然科学基金项目(2013GXNSFAA019327
2013GXNSFFA019004)
广西研究生教育创新计划资助项目(YCSZ2013067)
关键词
微震采集
同步采样
时钟分相算法
PID算法
micro-seismic acquisition
synchronous sampling
clock phase algorithm
PID algorithm
