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1.
Infrasonic Signal Detection and Source Location at the Prototype International Data Centre 总被引：1，自引：0，他引：1
D. J. Brown C. N. Katz R. Le Bras M. P. Flanagan J. Wang A. K. Gault 《Pure and Applied Geophysics》2002,159(5):1081-1125
—?This paper describes an automatic and interactive data processing system designed to locate impulsive atmospheric sources with a yield of at least one kiloton by detecting and characterizing the airborne infrasound radiated by the source. The infrasonic processing subsystem forms part of a larger system currently under development at the Prototype International Data Center (PIDC) in Arlington, Virginia where seismic, hydroacoustic, radionuclide and infrasonic methods are used to detect and locate impulsive sources in any terrestrial environment. Infrasonic signal detection is achieved via a coincidence detector which requires both the normalized cross correlation and the short-term-average/long-term-average ratio of a beam in the direction of maximum correlation to exceed predetermined threshold values simultaneously before a detection is declared. The infrasound propagation model currently used to infer travel-time information assumes the horizontal sound speed across the ground to be 320.0?m/s. This crude model is currently being replaced by a model which predicts travel-time information through a ray-tracing algorithm for acoustic waves in an atmosphere with seasonal representations for temperature and wind. A novel feature of the source location process is the fusion of all available arrival information, whether it be seismic, hydroacoustic or infrasonic to locate a single source where it is reasonable to hypothesize a common source. In its final configuration the infrasonic subsystem will routinely process data from the global 60-station International Monitoring System (IMS) infrasonic network currently under development. 相似文献
2.
一个紧密结构地震台网中心核心数据处理系统 总被引：1，自引：1，他引：0
介绍一个基于UNIX类操作系统的紧密结构地震台网中心核心数据处理系统。 该系统适用于复杂结构的数字地震台网中心, 支持以比较低的成本, 可靠地完成地震台网中心的核心任务, 可以接收来自串口和网络的实时地震波形数据, 支持虚拟数字地震台网组网要求的节点数据服务功能等。 该系统的数据服务协议具有实时性高、 通讯可靠、 适应范围广等特点, 可以满足包括地震预警在内的所有实时地震数据应用的需要。 系统结构紧凑, 自动化程度高, 安全, 稳定, 系统伸缩性大, 可以满足台站数目不大于100个的数字地震台网中心的需要, 同时也可以作为大型数字地震台网中心的处理节点, 构成大型数字地震台网中心的数据处理系统。 相似文献
3.
通过对现在的大震速报电话传输系统的问题分析,提出了相应的解决方法。结合当今的流行文件传输方式FTP技术,对台站速报数据的传输进行了改进,充分考虑到台站实际情况的复杂性、多样性,提供多种数据转换接口,并且所有这些工作都封装在程序包中进行,无须人为干涉,提高了速报速度,同时考虑到地震无法定位时需手工输入等情况,设计了手工输入模块,努力使速报数据能准确快速获得传输。最后对整个系统运行的效能进行了客观公正的分析,认为该系统是国家数字化地震台网中心利用各台卫星实时传输的地震信号进行处理后速报方法的有效补充。 相似文献
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本文首先对援印尼地震监测台网及数据处理系统的构建作了简要的介绍。 在此基础上对该台网系统的监测能力作了评估, 并选取试运行以来记录到的印尼地区32次大地震事件, 将系统自动产出的定位结果和USGS公布的结果进行了比对分析。 结果表明, 援建台网地震自动定位系统运行稳定, 对大地震的自动定位结果基本可信。 实现了2分钟以内对印尼境内及周边一些区域的强震自动产出首次定位结果并发出强震警报, 3～4分钟左右完成较精确的自动定位, 对于印尼地区6级以上地震, 自动定位系统可在5分钟内给出较精确的地震三要素。 援建系统不仅提高了印尼及周边区域的地震监测能力、 地震定位精度以及地震速报能力, 也为其海啸预警提供了有效保障。 相似文献
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震源机制解是地震学研究的重要组成部分, 它从一定程度上描述了震源的性质及其破裂过程, 对其正确、 全面地认识可深化理解地震的孕育、 发生和演化。 而地震波形自动反演系统的建立, 不仅实现了利用地震波形信息进行震源机制解的自动反演, 更重要的是加快了反演的速度, 充分体现了提取震源信息的实效性, 从而有力地帮助震情分析、 余震趋势预测、 震后救援等工作的展开。 本文系统地阐述了震源机制解反演方法, 总结了自动反演系统构建思路以及波形自动反演系统的实现, 为国内构建自动反演系统提供了可鉴的技术思路。 相似文献
7.
Junlun Li Huajian Yao Baoshan Wang Yang Yang Xin Hu Lishu Zhang Beng Ye Jun Yang Xiaobin Li Feng Liu Guoyi Chen Chang Guo Wen Yang 《地震研究进展（英文）》2022,2(2):100033
A rapidly deployable dense seismic monitoring system which is capable of transmitting acquired data in real time and analyzing data automatically is crucial in seismic hazard mitigation after a major earthquake. However, it is rather difficult for current seismic nodal stations to transmit data in real time for an extended period of time, and it usually takes a great amount of time to process the acquired data manually. To monitor earthquakes in real time flexibly, we develop a mobile integrated seismic monitoring system consisting of newly developed nodal units with 4G telemetry and a real-time AI-assisted automatic data processing workflow. The integrated system is convenient for deployment and has been successfully applied in monitoring the aftershocks of the Yangbi MS 6.4 earthquake occurred on May 21, 2021 in Yangbi County, Dali City, Yunnan in southwest China. The acquired seismic data are transmitted almost in real time through the 4G cellular network, and then processed automatically for event detection, positioning, magnitude calculation and source mechanism inversion. From tens of seconds to a couple of minutes at most, the final seismic attributes can be presented remotely to the end users through the integrated system. From May 27 to June 17, the real-time system has detected and located 7 905 aftershocks in the Yangbi area before the internal batteries exhausted, far more than the catalog provided by China Earthquake Networks Center using the regional permanent stations. The initial application of this integrated real-time monitoring system is promising, and we anticipate the advent of a new era for Real-time Intelligent Array Seismology (RIAS), for better monitoring and understanding the subsurface dynamic processes caused by Earth's internal forces as well as anthropogenic activities. 相似文献
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在VS2015开发环境下,使用C#语言编写国家地震台断记统计和批量补数自动处理程序,实现数据中断统计查询、数据采集器波形数据文件下载和上传波形数据文件至远程服务器的自动化。该自动处理程序在部分地震台使用以来,运行良好,数据完整率、连续率得到保障。 相似文献
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Jun Fan Tian-Chang Chen Wei-Bin Han Jian Zeng Si-Hua Zheng Akira Hasegawa Shigeki Horiuchi 《地震学报(英文版)》1998,11(3):375-379
Conclusions The real-time processing system of CTSN performs following: A/D conversion; automatic event detection; event data saving;
automatic measure of P and S arrivals; event location and print out the calculated results. It is corrected at ny moment by
using the off-line system. Since December 1993, this system has been operating normally in the CTSN. More than 4 000 earthquakes
have been recorded in the system. It has high accuracy in automatic picking P and S arrivals. The location of the earthquakes
determined by on-line system are close to those given in published catalogues which are determined by manual procedure. This
system can finish locate event in three minutes. It also gives satisfactory epicenter locations for distant events by inputting
manually S arrivals in the off-line system. The operation of this system had brought the technical superiority of the CTSN.
It not only reduces the labor intensity and simplifies the working procedure, but also makes our research facility into the
superior ranks in this field of our country.
In conclusion, the real-time processing system of seismic wave provides technical support for the daily requirements of monitoring
seismic activity as well as a lot of digital waveform data used seismic research in Sichuan area.
This subject is sponsored by the Scientific and Technical Committee of Sichuan Province. 相似文献
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A technique for automatic cross-well tomography based on semblance and differential semblance optimization is presented. Given a background velocity, the recorded seismic data traces are back-propagated towards the source, i.e. shifted towards time zero using the modelled traveltime between the source and the receiver and corrected for the geometrical spreading. Therefore each back-propagated trace should be a pulse, close to time zero. The mismatches between the back-propagated traces indicate an error in the velocity model. This error can be measured by stacking the back-propagated traces (semblance optimization) or by computing the norm of the difference between adjacent traces (differential semblance optimization).
It is known from surface seismic reflection tomography that both the semblance and differential semblance functional have good convexity properties, although the differential semblance functional is believed to have a larger basin of attraction (region of convergence) around the true velocity model. In the case of the cross-well transmission tomography described in this paper, similar properties are found for these functionals.
The implementation of this automatic method for cross-well tomography is based on the high-frequency approximation to wave propagation. The wavefronts are constructed using a ray-tracing algorithm. The gradient of the cost function is computed by the adjoint-state technique, which has the same complexity as the computation of the functional. This provides an efficient algorithm to invert cross-well data. The method is applied to a synthetic data set to demonstrate its efficacy. 相似文献
It is known from surface seismic reflection tomography that both the semblance and differential semblance functional have good convexity properties, although the differential semblance functional is believed to have a larger basin of attraction (region of convergence) around the true velocity model. In the case of the cross-well transmission tomography described in this paper, similar properties are found for these functionals.
The implementation of this automatic method for cross-well tomography is based on the high-frequency approximation to wave propagation. The wavefronts are constructed using a ray-tracing algorithm. The gradient of the cost function is computed by the adjoint-state technique, which has the same complexity as the computation of the functional. This provides an efficient algorithm to invert cross-well data. The method is applied to a synthetic data set to demonstrate its efficacy. 相似文献
12.
Optimum pilot sweep 总被引：3，自引：0，他引：3
The successful application of high-resolution seismic methods requires evaluating each element in the seismic system and ensuring that each part of the system contributes optimally to the success of the method. Unfortunately, unlike data processing, seismic signal generation is not carefully optimized. The purpose of our study was to optimize the source signal in order to better coordinate field operations with subsequent data processing to achieve their common objective. We developed an iterative method for a rational frequency distribution of the energy of a seismic source. The method allows the optimum amplitude spectrum of a source signal to be calculated, thus providing the best data quality at the end of the processing. We assume that the source signal is affected by a total transfer function, by the reflectivity function of a target interval, and by ambient noise, whose characteristics, if not known, can be estimated or measured in practice. The transfer function includes data processing other than the correlation stage and the final trace-optimizing filter. The variance of a reflectivity estimate is considered to be a measure of the data quality and improvement of the characteristic corresponds to a decrease in the variance. For this reason, a constrained Wiener deconvolution filter is used as the final trace-optimizing filter. It not only minimizes the variance of a reflectivity estimate but also ensures a specific signal-to-noise ratio. The method is made feasible by following the Vibroseis technique, primarily because of the versatility of the technique in controlling the signal spectrum. With the optimum amplitude spectrum obtained, the corresponding optimum pilot sweep can be readily calculated. Examples using synthetic data are presented to illustrate the method. 相似文献
13.
测震学综合应用软件系统在地震监测工作中的应用 总被引：1，自引：0，他引：1
简要说明了测震学综合应用软件系统的系统特点;详细介绍了该软件系统的功能;重点分析了该软件系统在地震监测工作中的应用,如在地震编目、序列自动编目、测震台网控制震级能力评定、辅助台网布设方案设计及地震现场应急等方面的应用。用户反馈的信息表明,测震学综合应用软件系统可以在地震监测中发挥重要作用。 相似文献
14.
A novel technique for automatic seismic data processing using both integral and local feature of seismograms 
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下载免费PDF全文 Ping Jin Chengliu Zhang Xufeng Shen Hongchun Wang Changzhou Pan Na Lu Xiong Xu 《地震科学（英文版）》2014,27(3):337-349
A novel technique for automatic seismic data processing using both integral and local feature of seismograms was presented in this paper. Here, the term integral feature of seismograms refers to feature which may depict the shape of the whole seismograms. However, unlike some previous efforts which completely abandon the DIAL approach, i.e., signal detection, phase identification, association, and event localization, and seek to use envelope cross-correlation to detect seismic events directly, our technique keeps following the DIAL approach, but in addition to detect signals corresponding to individual seismic phases, it also detects continuous wave-trains and explores their feature for phase-type identification and signal association. More concrete ideas about how to define wave-trains and combine them with various detections, as well as how to measure and utilize their feature in the seismic data processing were expatiated in the paper. This approach has been applied to the routine data processing by us for years, and test results for a 16 days’ period using data from the Xinjiang seismic station network were presented. The automatic processing results have fairly low false and missed event rate simultaneously, showing that the new technique has good application prospects for improvement of the automatic seismic data processing. 相似文献
15.
I. P. Passechnik 《Pure and Applied Geophysics》1973,103(1):424-432
Summary There are considered magnitude values distortions because of not taking into account the properties of links of the system where seismic waves are excited, spread and registrated. The links are: the source, the medium, the thickness of rocks, forming the upper part of seismo-geological section at the station region, seismic channel and processing methods of considered data. The system links are divided into nonoperating (source, medium) and operating (seismogeological section at the station region, seismic channel parameters, processing methods), which can be changed to a certain extent while registrating seismic oscillations.Strong distortion of narrow band shortperiod and longperiod instrumentation of seismic records is shown. This brings to considerable decreasing magnitude values comparing with the values determined by the records of broad band instrumentation. In order to decrease the magnitude distortion there is recommended the passing to registration. In order to decrease the magnitude distortion there is recommended the passing to registration of seismic oscillations by broad band receiving channels with large dynamic range of 100–120 decibel with magnetic tape digital registration and following processing of the data by the computers.There is pointed out that seismic stations installation at unweathered crystalline rocks is the most favourable, and a special attention is drawn to necessity of correct choice of the processing methods of the net stations data while calculating the averaged magnitude values.At present before the complete passing to broad band digital registration there is suggested to determine magnitudes in the international centers on the data by specially chosen stations supplied by most broad band instrumentation, using existing standard scales, practically coinciding with Gutenberg-Richter's scales. 相似文献
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中国数字地震台目前所采用的数据处理软件存在下列不足:1)不能对含lg震相的地震定位;2)不能计算mB、mb震级;3)不能自动生成月报;4)不能实现数据共享和独立完成地震速报;5)近震参数计算误差较大;6)地震定位效果不好。为此,我们基于VisualBasic软件平台,开发出智能化网络地震监控和实时数据处理系统。该系统除克服了以上不足外,还实现了数字地震仪工作状况的实时监控、地震参数计算、地震速报、各种地震单台定位、地震事件检索查询、地震编目、震相反推分析、数据传输等功能。该软件囊括了数字地震台全部日常工作,减轻了台站人员的工作量,有助于提高地震监测质量,充分发挥了数字地震仪的优越性。该系统在洛阳台近1年的试用中取得了较好的效果 相似文献
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地震P波震相到时与初动极性的精确读取是地震资料分析处理的重要步骤之一.本研究采用了一种新的高精度自动确定地震波P波震相到时与初动极性的概率分布的方法(POI方法,后同),在此基础上研究开发了一套自动化小震震源机制解的反演流程,并将其应用在云南小江断裂带周边区域的小震震源机制和构造应力场反演中.得到的震源机制与应力场反演结果与前人的研究一致,且与区域GPS观测结果和构造背景吻合度较好,显示该方法具有良好的应用前景,为高效分析密集台阵地震观测资料,开展小震震源参数测量与区域应力场反演提供了新的研究思路和技术手段. 相似文献
19.
地震P波震相到时与初动极性的精确读取是地震资料分析处理的重要步骤之一.本研究采用了一种新的高精度自动确定地震波P波震相到时与初动极性的概率分布的方法(POI方法,后同),在此基础上研究开发了一套自动化小震震源机制解的反演流程,并将其应用在云南小江断裂带周边区域的小震震源机制和构造应力场反演中.得到的震源机制与应力场反演结果与前人的研究一致,且与区域GPS观测结果和构造背景吻合度较好,显示该方法具有良好的应用前景,为高效分析密集台阵地震观测资料,开展小震震源参数测量与区域应力场反演提供了新的研究思路和技术手段. 相似文献
20.
李鸿吉 《地震地磁观测与研究》1995,16(4):55-60
数字地震资料的预处理是每个使用数字地震资料的学者所必然要遇到的基本问题。为避免波形处理中烦琐的手工劳动，最大限度地利用微机来完成绝大部分操作，实现波形处理的程序化，是国内外地震软件学者所追求的共同目标。本文在这方面作了探索，所开发的软件确实使数字地震波形预处理变得很轻松。 相似文献