共查询到18条相似文献，搜索用时 187 毫秒
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随着固体潮磁带记录的引用,在格式变换、取样、标定等方面产生了一些新问题,对1分钟间隔的固体潮磁带记录的取样和预处理已有讨论。由于固体潮观测装置又可以作为长周期的地震仪,5秒钟间隔的固体潮磁带记录,一方面有益于提高观测精度,另一方面又可用来研究地球的自由振荡,因此它是一种很有价值的记录方式。本文讨论这种记录的再取样及预处理的整个过程。 相似文献
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新一代ＣＤＳＮ台站磁带，是重要的ＣＤＳＮ数据存贮介质。本文叙述了编制程序解折其数据记录格式方法和实验过程，通过对实验结果讨论分析，揭示了该磁带的数据记录格式。 相似文献
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全球导航卫星系统（GlobalNavigationSatelliteSystem,GNSS）的应用日趋广泛,然而各接收机生产商提供的数据记录格式各不相同。国际上普遍采用RINEX（一种与接收机无关的转换格式）格式数据作为数据后处理的标准输入。RINEX格式从其出现至今经过了一系列演化,诞生了不同的版本。在实际应用中涉及不同版本的数据时。尤其是编程读写RINEX文件时,对读写数据格式定义的不恰当可能造成严重的错误。本文集中对RINEX迄今为止广泛应用的几个版本的观测数据文件的标准格式进行说明,并就不同版本RINEX格式观测数据文件的应用进行比较,结合我国正在建设的北斗卫星导航系统（BDS）引出关于数据文件格式方面的一些认识。 相似文献
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李鸿吉 《地震地磁观测与研究》1992,(5)
国际部署加速度仪台网(IDA)是全球性的数字化高增益长周期地震加速度观测系统,在北京和昆明设有观测台站。通过国际交换,我国可得到全球的 IDA 资料,这些资料急待我国学者开发与利用。在 IDA 的磁带数据文件中包含有两种不同的记录。一种是用 EBCDIC 码写成的说明,有台站名和起始时间等信息;另一种是二进制补码的整型数据记录。前者占1个记录,后者占18个记录.正确的使用 IDA 数据必须充分利用这两种记录所提供的信息。在 VAX11机上所研制的 IDA 解析软件为开发与利用 IDA 数据资源提供了方便. 相似文献
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为了进行西藏高原地区的爆炸地震研究,研制了一套模拟磁带记录系统。每台仪器包括三个两周的拾震器（LS-1型）、三个相应的低噪声线性放大器（DDF-5型）、三个调制器、一台低频磁带记录器（DCJ-1型）、石英钟、对时器和收音机。仪器频率范围是2周-20周（对速度）,时间误差小于0.1秒。采用抖动补偿和频率滤波的办法,使系统的信噪比提高到50分贝。系统的幅度误差小于10％。经过野外实地观测和资料整理分析,证明其性能和指标能够满足地壳与上地幔爆炸地震研究的需要。通过模/数转换器,把模拟磁带转录成数字磁带,可以在电子计算机上进行各种数字处理。 相似文献
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关于计算机在数字化地震前兆观测系统中的应用,首要的问题是实时地收集前兆数据。本文介绍的数字化前兆实时采集程序是在国产DJS—131计算机的支持下,在实时操作系统XRTOS的控制下,实时响应中断,实时采数;对采得的数据进行多种功能的判别、处理,并按一定格式编排,写入数字磁带,供进一步分析处理用。该程序主要应用于电信传输地震台网的前兆观测系统中。程序的设计思想及其处理方法可推广到任何其它的实时采集数据的系统中。 相似文献
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本文全面地描述了中国地震科技文献数据库(英文版)。该库在VAX 11/750小型计算机上,使用VAX数据检索、VAX公共数据字典软件进行设计。是一个联机检索系统。文献库收集五十余种中国编辑出版的科技期刊中,有关地震预报研究的论文。参考国內外文献著录准则,使文献记录格式标准化,通用化。一条记录长1898字节,其中文摘长1020字节。每年文献量约800余条。文献库磁带和软盘拷贝在国内外交换与出售。 相似文献
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李淑琴 《地震地磁观测与研究》1988,(5)
一、概述现代地震观测系统,已发展为数字观测系统。数字记录仪器越来越广泛地用于地震观测.近年来,我国陆续引进了 PDR-1、PDR-2、DP-200、DP-260/250等数字磁带记录仪及回放设备。我国的观测系统也出现了新的飞跃,由模拟观测系统发展为数字观测系统,使系统的记录动态范围由50dB 提高到100dB 以上。随着计算机科学技术的迅速发展,使资料高精度、高质量、高速度的数字处理方面都大大优于模拟系统。 相似文献
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人工爆炸地震野外数据处理装置 总被引：1，自引：0，他引：1
1988年底在华南地区连县-港口近400km的测线上,首次使用了中国科学院地球物理研究所研制的人工爆炸地震野外数据处理装置.该装置由AT型微机及必要的接口板和外围装置组成,能在野外条件下把模拟或数字记录仪记录结果以数字数据形式输入计算机,并进行显示、打印、存储等操作.由于成功地解决了诸如磁带信号直接屏幕扫描搜寻,时间信号自动识别、解码,钟差和零时信号屏幕光点比测,采样率随磁带速度自动调节,多通道长时间信号连续存储,数字滤波和再采样,用普通打印机快速打印高分辨率图形等技术问题,我们在野外记录后2-3天内即能绘出全测线120道记录的剖面图,达到了前所未有的高速度. 相似文献
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本文讨论取样间距为5s的固体潮磁带数据的重取样及消除强地震干扰的方法.所提出的多项式拟合平滑取样方法(PFSS)使读带、平滑、取样同步进行.读带一结束,计算机内存就有了按给定间距的取样结果.由于只对有关点作格式变换和预处理,故可以节省计算时间;由于只存取样结果,故可以节省计算机空间.因此,这种方法适用于小间距而延续时间长的固体潮磁带数据.采用功率谱分析,并对PFSS方法的结果作了检验,证明这种方法具有良好的滤波功能.为了消除强地震干扰所引起的畸变,采用Nakai方法并给出迭代程序,也用谱分析作了检验.校正后的观测数据,其谱分析结果与理论潮结果相似. 相似文献
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Dynamic tests of a concrete gravity dam are, for the first time, performed inside a centrifuge. Details of the experimental procedure, data interpretation, and results are presented. It is shown (in conjunction with a parallel paper) that these tests cannot only provide a direct assessment of certain aspects of dam safety, but more importantly provide a data base for possible non‐linear finite element code validation. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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A fast inversion technique for the interpretation of data from resistivity tomography surveys has been developed for operation on a microcomputer. This technique is based on the smoothness-constrained least-squares method and it produces a two-dimensional subsurface model from the apparent resistivity pseudosection. In the first iteration, a homogeneous earth model is used as the starting model for which the apparent resistivity partial derivative values can be calculated analytically. For subsequent iterations, a quasi-Newton method is used to estimate the partial derivatives which reduces the computer time and memory space required by about eight and twelve times, respectively, compared to the conventional least-squares method. Tests with a variety of computer models and data from field surveys show that this technique is insensitive to random noise and converges rapidly. This technique takes about one minute to invert a single data set on an 80486DX microcomputer. 相似文献
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J. F. TRUHLAR 《水文科学杂志》2013,58(4):409-417
Abstract The Pennsylvania Department of Transportation and the US Geological Survey are cooperating in several field studies to evaluate sediment control measures used during highway construction. Among the parameters being monitored are suspended sediment concentration and turbidity. Sediment loads are calculated from suspended sediment and water discharge data, but some sediment loads must be determined indirectly because it is virtually impossible to obtain sufficient suspended sediment samples to define all runoff conditions adequately. Sediment discharge-water discharge correlation curves have proved unreliable for streams affected by highway construction, so an alternative method using the turbidity record was developed during these studies. The field data reveal a good correlation between daily mean discharge-weighted turbidity and daily mean discharge-weighted suspended sediment concentration. Turbidity is monitored and recorded continuously, and the daily mean discharge-weighted turbidity is calculated from the turbidity and water discharge data. During periods when there are insufficient suspended sediment data, the daily mean discharge-weighted suspended sediment concentration is determined from the turbidity-sediment correlation and used with the daily mean water discharge to calculate a daily sediment load. This method of determining sediment loads from the turbidity record suggests a possiblity for computation of sediment loads by computer. Instrumentation now in use for recording water quality parameters on digital punch tape could be used to record the output from a turbidimeter. Then, for streams having a good correlation between suspended sediment concentration and turbidity, simultaneous water discharge and turbidity data could be used to determine sediment loads by computer. 相似文献
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S.E. Pirhonen S. Nurminen U. Luosto H. Korhonen 《Physics of the Earth and Planetary Interiors》1979,18(2):121-126
This paper deals with the Finnish seismic array, which in its present state consists of two tripartite arrays, HESA and JYSA. The first of these arrays, situated near Helsinki, has been in continuous operation since 1964 and uses analog recording by frequency-modulated telemetry. The JYSA array is sited in central Finland near the town of Jyväskylä. This array consists of three substations equipped with vertical-component SP seismometers. The signals are transmitted by digital FM telemetry in the UHF band and recorded at Helsinki on magnetic tape. Events are detected visually from monitoring drums. The digital data of the events detected are handled by a microprocessor with a graphic display and fed to a Burroughs 6700 analysing computer.Comparison with the NORSAR array indicates that at frequencies below 2 Hz the absolute noise level at JYSA is about 6 dB lower, but above 2 Hz the noise level for single instruments at the two arrays is about the same. As regards detection capability, the incremental threshold is about the same for JYSA as for Hagfors and 0.5 magnitude units higher than for NORSAR, but 0.5 magnitude units lower for JYSA than for the WWSSN station NUR in southern Finland. 相似文献
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CONTRIBUTION DU TRAITEMENT NUMERIQUE A L'ANALYSE ET A INTERPRETATION DES ENREGISTREMENTS REFRACTION*
R. PERALDI 《Geophysical Prospecting》1969,17(2):126-164
The tools used in digital processsing have received little application, to date, to refraction seismic. It seems however that some problems encountered in the analysis of refraction records could be solved through techniques which are of common use in processing of reflection seismic data (correlation, stacking, f and k filtering). The experiments made with some of these techniques revealed the possibility of a more complete refraction record analysis, allowing the study of later arrivals. The interpretation of these records could also, to a fairly large extent, be automated by means of digital processing. While recording, some care ought to be taken to allow identification and interpretation by digital processing of as many events as possible. However, the results shown here have been obtained from fairly old analog records, for which no particular care had been taken, which makes it possible to complete and revise the interpretation of previous studies using the same processing techniques. Long line refraction shooting is justified for marine surveys in some areas, particularly where reflection is disturbed by singing; improvements in analysis and interpretation would therefore prove very useful for a faster and more thorough interpretation. 相似文献
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A Parallel PCG Solver for MODFLOW 总被引：2，自引：0，他引：2
In order to simulate large-scale ground water flow problems more efficiently with MODFLOW, the OpenMP programming paradigm was used to parallelize the preconditioned conjugate-gradient (PCG) solver with in this study. Incremental parallelization, the significant advantage supported by OpenMP on a shared-memory computer, made the solver transit to a parallel program smoothly one block of code at a time. The parallel PCG solver, suitable for both MODFLOW-2000 and MODFLOW-2005, is verified using an 8-processor computer. Both the impact of compilers and different model domain sizes were considered in the numerical experiments. Based on the timing results, execution times using the parallel PCG solver are typically about 1.40 to 5.31 times faster than those using the serial one. In addition, the simulation results are the exact same as the original PCG solver, because the majority of serial codes were not changed. It is worth noting that this parallelizing approach reduces cost in terms of software maintenance because only a single source PCG solver code needs to be maintained in the MODFLOW source tree. 相似文献