分布式地震数据采集同步技术研究

发布时间：2018-05-01 11:23

本文选题：分布式 + 地震数据采集　；参考：《西南科技大学》2017年硕士论文

【摘要】：地震勘探技术是石油勘探中有效的方法之一,地震勘探中的所使用的数据采集系统正朝着三分量、高密度、多道数、分布式的大规模数据采集方向发展,地震数据的采集同步性将直接关系到后续的地震资料处理与解释工作的准确性,在分布式地震数据采集系统中是一个重要且关键的因素。由于分布式地震采集系统中节点数的增多以及相互之间较为独立,也给其实现数据的采集同步带来了一定的难度。分布式系统中采集同步常用的是给数据加上时间戳的方法,其基本要求是需要各个节点的时钟保持一致,传统的网络授时方法由于其节点数的增多,增加了网络授时方法的复杂度及难度。针对上述问题,本文依托于"复杂山地多波宽频带地震数据采集系统研制"国家自然科学基金重大科研仪器设备研制专项支持,对分布式采集系统中的单节点数据采集同步、采集节点的时钟同步的问题展开研究与设计。单节点数据采集同步研究与设计中,本文基于STM32F429ZET6低功耗高性能微处理器实现32位高精度地震数据采集节点设计,在单采样间隔时间内通过硬件SPI通信协议实现采集节点三分量数据的并行采集同步。设计完成32位A/D芯片ADS1282的转换电路、采集电路、电源电路及相关下位机驱动程序的开发,经测试,单节点3路信号同步精度在2ns以内,信号线性相关度为99.99%,具有良好的同步水平。采集节点的时钟同步研究与设计中,本文结合GPS时间无累计误差、本地时钟短短期的稳定性较好的特点。设计完成基于GPS时钟作为中心时钟对采集节点进行授时,同时利用其高精度的1PPS秒脉冲对本地时钟频率进行测量与校准,降低本地时钟漂移对时钟走时带来的误差。设计完成基于GPS的本地授时系统相关软硬件设计,对本地时钟频率测量、调整及时间戳生成方法进行设计与实现,经测试,节点间GPS授时1PPS同步信号误差为30ns以内,单节点时间戳误差在0.1us以内,节点间时钟误差在10us以内。通过本文的研究,为地震数据采集中的单节点数据采集同步以及多节点的时钟同步的问题,研究并设计了一种有效的方法,为地震数据采集的同步问题提供了一种有效的解决途径。
[Abstract]:Seismic exploration technology is one of the effective methods in petroleum exploration. The data acquisition system used in seismic exploration is developing towards the direction of large-scale data acquisition with three components, high density, multi-channel number and distributed data acquisition. The synchronization of seismic data acquisition is directly related to the accuracy of subsequent seismic data processing and interpretation. It is an important and key factor in distributed seismic data acquisition system. Since the number of nodes in distributed seismic acquisition system is increasing and each other is independent, it is difficult to realize the synchronization of data acquisition. The common method of collecting synchronization in distributed system is to add time stamp to the data. Its basic requirement is to keep the clock of each node consistent. The traditional network timing method is due to the increase of the number of nodes. The complexity and difficulty of the network timing method are increased. In view of the above problems, this paper relies on "the development of multi-wave broadband seismic data acquisition system in complex mountainous areas", which is supported by the National Natural Science Foundation of China for the development of major scientific research instruments and equipment, and synchronizes the single node data acquisition in the distributed acquisition system. Research and design of clock synchronization of acquisition node. In the research and design of single node data acquisition synchronization, the 32 bit high precision seismic data acquisition node is designed based on STM32F429ZET6 low power and high performance microprocessor. In the time of single sampling interval, the parallel acquisition synchronization of three component data is realized by hardware SPI communication protocol. The conversion circuit, acquisition circuit, power supply circuit and related lower computer driver of 32-bit A / D chip ADS1282 are designed and developed. After testing, the synchronization accuracy of single node 3-channel signal is within 2ns. The linear correlation of the signal is 99.99 and has a good synchronization level. In the research and design of clock synchronization of acquisition nodes, this paper combines the characteristics of GPS time with no accumulative error, and the local clock with short term stability. The timing of the acquisition node based on the GPS clock is designed and the local clock frequency is measured and calibrated by using its high precision 1PPS second pulse to reduce the error caused by the local clock drift. The software and hardware of the local time service system based on GPS are designed and completed. The method of local clock frequency measurement, adjustment and time stamp generation is designed and implemented. After testing, the error of GPS timing 1PPS synchronization signal between nodes is within 30ns. The time stamp error of single node is within 0.1us and the clock error between nodes is within 10us. Through the research of this paper, an effective method is studied and designed for single node data acquisition synchronization and multi-node clock synchronization in seismic data acquisition. It provides an effective way to solve the synchronization problem of seismic data acquisition.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P631.4;TP274.2

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