分布式无线地震数据采集同步技术研究

Study of synchronization technology of Distributed Wireless Seismic Data Acquisition

摘要:

针对目前分布式无线地震数据采集中由于采集节点增多、无线传输延时等因素导致的各采集节点间数据采集同步精度不高的问题,研究并设计了一种针对分布式无线数据同步采集中各个节点同步授时以及对采集数据包进行精确时间标记的方案。采用GPS(Global Positioning System)授时技术对各个采集节点时钟进行授时,同时利用GPS精准的秒脉冲对本地压控晶振器频率误差进行实时修正。采用在地震采集数据包中加入精确的时间戳信息的方法,保证了各个节点间同步误差限制在0.1ms以内。即使在GPS失效的情况下,压控晶振器和计数器联合作用仍可保证各节点同步采集稳定工作6小时。

Abstract:

Low synchronization precision of data acquisition is an annoying problem in distributed wireless seismic data acquisition due to the increasing of the acquisition nodes and wireless transmission delay. In order to result this problem, what is put forward is that a scheme of synchronized timing to each node for the synchronous acquisition of the distributed wireless data and accurate time tagging on data packets. In this scheme, GPS (Global Positioning System) timing technology is utilized to issue the real time to the clock on each node for data acquisition, and GPS precise second pulse is also used to correct frequency error of local voltage controlled crystal oscillator so as to suppress the cumulative errors caused by non-synchronization between the nodes. By adding the time stamp information accurately in the seismic data acquisition, ensure that each node between the time synchronization error is limited within 0.1us. Even if the GPS signal loss, voltage controlled crystal oscillator and a counter joint action can ensure each node synchronous acquisition stable work 6 hours.