Location Calibration Data for CTBT Monitoring at the Prototype International Data Center

—?Ground-truth information is essential for location calibration of the International Monitoring System network being developed under the Comprehensive Nuclear-Test-Ban Treaty. The objective of the calibration effort is to improve the accuracy of seismic event locations and to reduce the size of the error ellipse, both in automatic and in human analyst-reviewed bulletins, in order to meet the On-Site Inspection requirement for the size of the inspection area. Several databases were compiled and are maintained at the Prototype International Data Center (PIDC) to support calibration efforts. The Nuclear Explosion Database contains most readily accessible information about all nuclear explosions worldwide. The events in the Calibration Event Bulletin (CEB) carefully selected well located events from the PIDC Reviewed Event Bulletin and relocated using additional arrivals from regional networks requested from various National Data Centers. The Ground-Truth Database contains carefully selected events with known or well estimated location accuracies from the Nuclear Explosion Database, CEB, as well as from bulletins of U.S. National Earthquake Information Center and International Seismic Centre. It also contains data on chemical explosions and quarry blasts when confirmed by local or national authorities. Ground-truth events are subdivided into various ground-truth categories according to their location accuracy. The databases have been used in various calibration studies to derive and test corrections to improve event locations. Several location calibration techniques are briefly described. The validation test for any proposed operational change requires that the results meet the location calibration metrics developed and implemented at the PIDC.     

High-Frequency Hydroacoustic Monitoring in an Underground Iron Mine

The monitoring of the stability of old mines constitutes an important research objective for our institution, BRGM. The study reported here shows the contribution of high-frequency (>30 kHz) acoustic emissions to the detection of the damage within a rock mass, during an experiment within a pilot site of an old flooded iron mine. The experiment consisted of recording all the hydroacoustic events in a broad frequency band (between 30 Hz and 180 kHz), during 18 months. The monitoring network has been calibrated by a triggered block fall that made it possible to highlight a relationship between the occurrence of high-frequency/low-frequency hydroacoustic emissions and rock falls. The events recorded have been associated with the micro-failure of the rock mass near the roof, prior to the detachment of the blocks. This monitoring showed important high-frequency hydroacoustic activity, which may be associated with mechanical instabilities generated by the evolution of water pressure during the experiment. In conclusion, the high-frequency hydroacoustic activity appears to be a good indicator of instability and, therefore, this new technique constitutes a promising tool for monitoring abandoned underground cavities.     

Radioxenon Time Series and Meteorological Pattern Analysis for CTBT Event Categorisation

Understanding radioxenon time series and being able to distinguish anthropogenic from nuclear explosion signals are fundamental issues for the technical verification of the Comprehensive Nuclear-Test-Ban Treaty. Every radioxenon event categorisation methodology must take into account the background at each monitoring site to uncover anomalies that may be related to nuclear explosions. Feedback induced by local meteorological patterns on the equipment and on the sampling procedures has been included in the analysis to improve a possible event categorisation scheme. The occurrence probability of radioxenon outliers has been estimated with a time series approach characterising and avoiding the influence of local meteorological patterns. A power spectrum estimator for radioxenon and meteorological time series was selected; the randomness of the radioxenon residual time series has been tested for white noise by Kolmogorov–Smirnov and Ljung–Box tests. This methodological approach was applied to radioxenon data collected at two monitoring sites located at St. John’s, Canada and Charlottesville, USA, equipped with two different noble gas systems. It shows different feedback with local meteorological patterns and randomness for the radioxenon data recorded at the selected sites of St. John’s and Charlottesville as well as a different occurrence probability of the outliers in the normalized radioxenon original and residual time series.     

CTBT国际监测系统水声监测网络概况

介绍全面禁止核试验条约（CTBT）国际监测系统（IMS）水声监测网络的组成、类型、分布及其监测能力,从台站的地理位置选择、勘址条件及台站构成、性能指标等方面,详细阐述H-相和T-相水声台站的建设和发展,并分析新一代水听器台站的设计理念及研发测试进展,以期为相关技术研究和我国水声台站建设提供参考。     

一种数据归档机制的实现

介绍了国际数据中心自动数据服务的方式,研究了国家数据中心数据处理过程中请求和获取国际数据中心非连续数据的方法,在此基础上设计了向国际数据中心获取数据的邮件数据请求代理程序,该程序可通过解析邮件,存储邮件数据请求者与请求数据的逻辑关系,实现了邮件数据的请求代理,在国家数据中心每日数据请求总量有限制的条件下,实现了数据的共享,满足对国内授权用户的需求,经过实际运行考验,证明程序稳定可靠,达到了设计目标。     

发电厂建（构）筑物沉降监测数据分析

发电厂设备较多,结构复杂,危险性较大,必须对其建（构）筑物进行沉降和变形监测。以湛江奥里油发电厂为例,在沉降观测的过程中,根据各个建筑物的沉降情况,进行了沉降趋势分析,针对湛江奥里油电厂建筑物沉降的特点,提出发电厂在建设（包括减载）及运营期间应按设计或相关规范要求,对建筑物及其周围进行沉降监测,以便掌握建筑物的沉降现状和规律,对发电厂的安全运营具有重要的参考价值。     

地震前兆数据监视与管理系统

在北京十三陵地震台建设了一个高度集成的地震观测监控系统, 将原来分散的观测项目(如测震、 GPS、 气氡、 气汞、 电磁波、 地电场等测项), 改造为集中到一台服务器管理, 在一个监控平台上统一实现了对台站数据的收集、 入库、 管理、 处理、 监控等业务; 对这些观测项目可以在控制台上直接取数并将数据入库; 初步实现了观测数据的收集、 数据处理、 数据管理、 数据监控的软件管理系统, 减少了系统维护工作量, 方便台站工作人员操控。 监控系统的地震前兆数据监管软件系统DataMonitor可准实时监视数据, 检查数据的异常和到达情况, 并向台站数据管理人员告警; 可对数据库数据进行统计, 包括数据到达情况统计、 缺数统计、 数据连续率统计等, 并可按用户定制的测项分类进行统计。 该系统还提供多种前兆数据处理方法, 实现对前兆数据的各种常规分析处理。 地震前兆数据监视与管理系统已在北京十三陵地震台应用, 满足了数据管理人员日常工作需要, 可及时方便地掌握数据的情况并对观测系统进行维护。     

Remote Data Collection and Control for Hydrogeologic Monitoring

A hydrogeologic field experiment, conducted at a research site some 125 miles (200km) from the home base, used commercially available computer controller technology for data collection and experimental control. A telephone line connected to the equipment facilitated the downloading of data, provided a means of remotely monitoring the operating performance, and made it possible to adjust the monitoring procedures.
This experiment demonstrated the benefits of a remotely controlled data acquisition system for a long-term investigation. Identification of problems and the adjustment of the sampling algorithm by telephone reduced costly travel time. The considerable amount of data collected, the data evaluation techniques, and the continuous monitoring, provided a high degree of confidence in the results.     

地震监测数据实时传输与汇聚系统

地震监测数据实时传输与汇聚是实现我国地震观测系统数据汇集处理工程化、运维管理智能化以及地震监测服务体系现代化的基础.新升级研发的地震监测数据实时传输与汇聚系统实现了地震监测数据的实时波形数据流服务,其具有丰富的适配器用于汇集地震监测台站或数据中心的实时地震波形或触发信息数据流.新系统支持快流/慢流混合传输和预警数据低延...     

佛开高速九江大桥振动监测数据初步分析

佛开高速九江大桥全长1819.16m,主桥采用六孔一联、最大跨度160m的变截面预应力砼连续箱梁。为实时监测桥梁结构振动状况和记录大型桥梁真实地震反应,在九江大桥主桥上架设了总计23通道的强震动监测系统。简要介绍了该监测系统的测点布置、系统构成和技术特点,并对系统试运行期间的加速度记录进行了峰值、频谱和模态分析,得到了箱梁前六阶模态频率变化曲线,并与现场实测模态参数进行了比较验证。研究识别出的模态频率的长期变化可以为桥梁结构的健康监测和损伤评估提供参考依据。     

甘肃大地电场的变化特征分析

对甘肃省平凉、松山、古丰、山丹、高台、嘉峪关、瓜州7个台站的地电场分钟值、小时值的日变特征进行了对比,对2012年3月地电场小时值进行了频谱分析,同时结合地磁场H分量、分量应变(固体潮)进行了对比分析。结果表明:1地电场静日的日变化都很明显,呈明显"双峰"和"单谷"形态,并且NS向与EW向变化形态基本相同;各台站同测向及相互之间的自相关系数基本在0.85;不同台站之间同测向的相关系数多数在0.75以上;这是地磁场H分量与固体潮共同影响的结果。2通过频谱分析各台站的优势周期主要以12h和8h为主,但存在差异性,谱值最大相差20倍。3各台站的日变幅也不尽相同,其中,差异性主要表现为与地磁场和固体潮影响量的差异性,并与台站的位置、地质构造、电性结构、浅层电阻率等有很大关系。     

SQL Server数据库中数据的安全监控

本文主要阐述了作者在工中遇到的SQL Server数据库中一些重要数据泄漏或是异常变动现象,随后通过各种技术手段追踪数据异常变更的根源的学习研究过程.从而达到了对日常工作中的重要数据进行安全监控、跟踪相关操作的目的,同时,也为各类数据的安全性、准确性提供了坚实的保障.     

Ten Years of Development of Equipment for Measurement of Atmospheric Radioactive Xenon for the Verification of the CTBT

Atmospheric measurement of radioactive xenon isotopes (radioxenon) plays a key role in remote monitoring of nuclear explosions, since it has a high capability to capture radioactive debris for a wide range of explosion scenarios. It is therefore a powerful tool in providing evidence for nuclear testing, and is one of the key components of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The reliability of this method is largely based on a well-developed measurement technology. In the 1990s, with the prospect of the build-up of a monitoring network for the CTBT, new development of radioxenon equipment started. This article summarizes the physical and technical principles upon which the radioxenon technology is based and the advances the technology has undergone during the last 10 years. In contrast to previously used equipment, which was manually operated, the new generation of radioxenon monitoring equipment is designed for automated and continuous operation in remote field locations. Also the analytical capabilities of the equipment were strongly enhanced. Minimum detectable concentrations of the recently developed systems are well below 1 mBq/m³ for the key nuclide ¹³³Xe for sampling periods between 8 and 24 h. All the systems described here are also able to separately measure with low detection limits the radioxenon isotopes ^131mXe, ^133mXe and ¹³⁵Xe, which are also relevant for the detection of nuclear tests. The equipment has been extensively tested during recent years by operation in a laboratory environment and in field locations, by performing comparison measurements with laboratory type equipment and by parallel operation. These tests demonstrate that the equipment has reached a sufficiently high technical standard for deployment in the global CTBT verification regime.     

On the Need for Accurate Monitoring of the Geomagnetic Field during Directional Drilling in the Russian Arctic

Izvestiya, Physics of the Solid Earth - Abstract—The readings of well magnetometers used in directional drilling may be distorted by geomagnetic storms and substorms. These distortions occur...     

Architecture and critical technologies of seismic information system in CTBT verification

Introduction Seismic monitoring is one of the most important approaches for ground-based nuclear explo-sion monitoring (CTBTO, 1998). The trend in this research field is to improve the monitoring ca-pability for low magnitude seismic events in regional scales. Seismic monitoring mainly includes detection, location, identification and characterization of seismic events. The correctness and accuracy of all of them depend on the quality of seismic re-cords and the degrees of uncertainties of ge…     

A Systematic Approach for Evaluating the Quality of Ground Water Monitoring Data

The recognition and assurance of the quality of ground water monitoring data are crucial to the correct assessment of the magnitude and extent of a ground water contamination problem. This article addresses an approach being developed to systematically evaluate the quality of a given set of ground water monitoring data collected during site investigation/ remedial action efforts. The system consists of a checklist of criteria, grouped into four major categories, which can be applied to laboratory or field measurements.
The first category, basis of measurement, considers whether the appropriate sampling, boring and/or analytical methods were chosen to obtain the measurement and the limitations of each method. Secondly, application of the method is assessed. This includes examination of the extent to which procedures were correctly performed, the use of quality control measures and calibration, and possible sources of error in the measurements. Third, evaluation of applied statistical methods is made, with consideration given to which statistics are meaningful in a given context and whether measurements are reproducible. The final category, corroborative information, considers whether independent data or other information are available that add credibility to the values measured.
In this approach, a "high quality" data value is defined as one in which accuracy is supported by meeting the preceding criteria. When accompanied by precision information, high quality data allow for defensible assessments and actions. This evaluation system is useful in developing monitoring programs and in guiding documentation of field and laboratory methods during data collection. It relies heavily on experienced judgment and can be catalyst for the beneficial exchange of knowledge and ideas among ground water professionals.     

地震监测数据三维交互式实时显示系统的开发

随着中国地震局"十五"网络项目的完成,云南省测震台网的日常地震监测工作都基于网络数据库系统,而现有的数据显示系统未与数据库系统有效结合。本文结合"十五"中国数字地震观测网络项目数据库系统,运用三维数据可视化、交互式图形界面技术开发了可实时显示三维地震监测数据信息的软件系统,改变了原有显示系统实时性、可操作性差和无法显示地震数据三维空间信息及时空变化关系的状况。     

前兆观测数据监视及异常自动识别软件系统

研制了前兆观测数据监视及异常自动识别软件系统。该软件可对前兆数据的上报情况和各测项的异常情况进行自动检测和报警。对系统进行了概述,从八个方面对系统功能的实现予以阐述。该软件的应用大大提高了工作效率。