链式系统中信号远距离传输延时的在线测量方法

针对地震勘探系统结构成链式、采集节点多,全局主时钟和系统控制命令在其间传输延时大,而且采集节点间产生的延时不同且未知,导致不同采集通道间同步采集误差不易得到精确校正而影响同步精度的问题,提出了一种实时在线测量信号传输延时的回传模型和方法,采用链路复用技术,用同一根下行链路传输线实现从预处理模块到所有采集节点传输延时的精确测量,并能同时实现延时量向各采集节点一对一地传输。在进行链式系统设计时,本文方法能为后续同步采集误差的精确校正提供精确的延时依据。最后,建立了具有3个采集节点的实验系统,实验结果验证了本文方法的有效性。

Real-time online measurement of the transmission time delay in long-distance chained systems

A lot of acquisition nodes are arranged in a straight line in seismic streamer,so there is large transmission time delay for the signal from one node to another.Meanwhile,different nodes generate different transmission time delays which are unknown;therefore,the delay time can not be accurately corrected,causing bad result of synchronization accuracy.To solve this problem,a model of "the signal return" and a measuring method of the transmission time delay were proposed.Employing the link multiplexing technology,the transmission time delay from the pre-processing module to all nodes can be measured accurately through the same clock signal line only,and the transmission delay time with each node can be transmitted to the corresponding node.This can provide a precise delay time,which allows the error of delay time to be accurately corrected.Experiment results with three nodes demonstrate the effectiveness of the proposed method.