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西宁地震台FHD数字化核旋仪从2006年10月安装以来,一直与模拟仪器并行工作。二者采样率不同,所测的量也不相同。在对西宁地震台磁变仪的记录图纸进行数字化转换、生成分钟值的基础上,对FHD仪和磁变仪的观测结果进行对比分析。结果表明:数字FHD仪比三分量磁变仪更加准确地记录了当地地磁场的变化,数字仪器的观测资料明显优于模拟仪器。 相似文献
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随着数字地震监测仪器的普及和应用,人工、模拟地震观测仪器逐渐被数字仪器所取代,记录方式也由整时记录变成分记录和秒记录。数字仪器在多年运行中,曾出现这样或那样的故障,本文重点通过对多年形变数字观测系统内部所出现的故障,进行分析与讨论,以便在观测工作中更好把握仪器的状况和对仪器出现的故障进行准确分析判定,及时对仪器存在的问题和故障进行解决处理,从而最大程度减少观测数据的断记。 相似文献
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本文利用标定信号的数字记录和模拟记录,参考已有的模拟记录的幅频特性,计算求得了成都遥测台网(CTSN)数字记录系统的仪器响应,其幅频特性曲线的形态与模拟记录的大致相同,而高于10Hz时,随机干扰成分较大,因此处理这套系统的数据时,应尽量选取低于10Hz的信号。 相似文献
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石棉川-02井系国家基本井,其井水位观测值对附近区域内的地震有比较敏感的前兆反映,在进行地震前兆数字化技术改造后,处于试记和调试阶段的LN-3型数字水位仪,记录到了一些地震前兆信息。LN-3型数字水位仪与SW40-l型浮子式机械水位仪相比,不仅信息传递快,而且记录了更丰富的有用信息。 相似文献
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南极中山站地磁台的建设与观测研究 总被引:1,自引:0,他引:1
南极中山站于1991年3月建立临时地磁台,1992年2月建立正式地磁台,台上建有地磁观测室、记录室和各种探头室.它们均采用高架结构和用无磁性材料建成;能保温、防潮、防积雪和抗强风.1991~1993年分别安装有数字化地磁仪,地磁脉动仪,哨声与VLF仪和地震仪,并不断获得极区地磁与高空物理资料.1991年与1992年中山站地磁观测报告(第一卷与第二卷)已整理成册,资料分析表明,极区地磁扰动与中低纬区地磁扰动特征有很大差异,这些差异主要是由极区各种电流体系所造成. 相似文献
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Summary A new instrument has been designed for recording the horizontal components of tidal variations of the Earth's field of gravity and of tidal and non-tidal tilts of the Earth's crust. After justifying the use of the individual constructional elements, the functional model of the photo-electric compensating tiltmeter, constructing in the Geophysical Institute of the CSAS and installed at the tidal station in the Anna mine, Píbram, is described. Special attention is devoted to the sensitivity and recording azimuth of the tiltmeter and to the practical determination of these quantities. A high and constant sensitivity, the invariance of the recording azimuth and the possibility of simple automation of the whole evaluating procedure are the main advantages of the proposed instrument. In the conclusion some of the experience gained from test operations is discussed. 相似文献
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具有数字与模拟特色的555时基集成电路是一种多功能电子器件。因其内部含有电压比较器、基本R—S触发器、放电电路及驱动电路等,辅以适当外围分立元件后,被广泛应用于单稳态电路、施密特触发器、多谐振荡器、幅度鉴别器及电压频率变换等。笔者根据地震台站观测仪器性能,结合测震、地磁及形变观测工作的需要,以555时基集成电路为核心元件,在时钟脉冲延时、定时控制及多谐振荡电路等方面小改小革,为提高台站模拟仪器时间服务精度及节能、地震仪应急工频替换电路等作了些尝试。 相似文献
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新疆数字地震台站观测动态范围和台基噪声的分析 总被引:2,自引:0,他引:2
介绍了新疆数字地震台仪器的配置,对新疆23个数字地震台站台基噪声进行分析计算。台站的观测动态范围,反映了观测仪器本身的性能和台基环境干扰背景的水平,有效动态范围大小反映记录地震信号的最大能力。台站(台网)的监测能力不仅取决于仪器的性能,而且还与台基的噪声背景有关。得出了各地震台台基的脉动噪声的均方根值、观测动态范围、地噪声功率谱。有效观测动态范围的大小与数字地震仪的种类和配置有关。新疆23个数字地震台中的21个台的台基地动噪声在1~20 Hz内符合中国数字测震台网技术规程的要求,而另外2个台,即二宫和石河子数字地震台没有达到规定指标。 相似文献
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W. F. DONNELL 《Geophysical Prospecting》1967,15(2):246-261
The use of digital recorders and computers in seismic exploration promises major enhancement of the quality of final documents available to interpreters. The ultimate objectives of recording and processing remain what they always have been: 1 Record the reflection wavelet as a function of time; this requirement has been met with satisfactory accuracy for a number of years. 2. Record the reflection wavelets with sufficient fidelity to permit the interpreter to recognize them. Various factors affect our ability to achieve this second objective. Certain recording errors are associated with digital recording systems. However, an understanding of the sources of error will enable the operator to use his system properly and to estimate the noise level or inaccuracy of field recordings. Field operations do not require rigorous error analysis; in most cases a satisfactory approximation can be obtained from simple calculations. Three types of “noise”–seismic, instrument and power line–introduce errors. Factors which contribute to over-al recording system error include specifically input noise, power supply ripple, crosstalk, A-D conversion error, quantizing noise, aliasing, distortion. Examination of each component of a recording system, permits the determination of its ultimate effect on the over-all noise level–or error level–of the entire system. Many of the error sources produce statistically independent noise which is not correlative. Where this is true, error voltages from various sources may be combined by taking the square root of the sum of the mean square noise voltages, giving a result slightly greater than the largest single voltage if one source is much greater than any other source. This simplification can be used to estimate over-all system noise levels. Distortion and crosstalk depend on signal amplitude and should be added algebraically in each category. Each final sum should be used as a statistically independent noise source with respect to other system noise sources. Using the foregoing examples and simplified system for estimating over-all system noise, and assuming that much of the distortion (which limits signal/instrument noise ratio to 54 db) can be removed by filtering, we determine that the combined effect of all sources of error is to reduce the system S/N ratio to approximately 74 db. With proper care digital field recording systems can produce very good field records, and exotic computer processes can enhance signal and reduce various forms of noise. However, one always must recall that the level of confidence which one can place in an interpretation of seismic data must be dependent on a knowledge of the accuracy of the basic data. 相似文献
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Determination of the surface composition at various sites on the planet Mars will provide information essential to a better understanding of the geologic history of this complex planet. A spectrometer based upon the X-ray fluorescence method of elemental analysis has been developed in an ultraminiature, rugged form suitable for a spacecraft mission to Mars. The instrument employs two radioisotope sources (55Fe and109Cd) which irradiate adjacent areas on a regolith sample. Fluorescent X-rays emitted by the sample are detected by four thin-window proportional counters. Using pulse-height discrimination, the energy spectra are determined. Virtually all elements above sodium in the periodic table are detected if present at sufficient levels. Minimum detection limits range from 30 ppm to 2%. depending upon the element and the matrix. For most elements, they are below 0.5%. Accuracies also depend upon the matrix, but are generally better than ± 0.5% for all elements of atomic number greater than 14. Elements below sodium are also detected, but as a single group. Ambiguities of identification of the elements producing the observed spectra are minimal. Exotic geological materials are, therefore, just as susceptible to analysis as are the more common rocks. A computer model of the instrument has been developed and tested. This model was used to optimize instrument parameters during the design phase, and has now been expanded to perform automatic analysis of the output data. 相似文献
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通过会昌台数字与模拟地震记录到的多个地震事件进行对比分析,认为前者在记录带宽、获取更多的地震动物理量、记录波形能力及可操作性等方面具有显著的优势,数字观测完全可以取代模拟观测;对两种记录计算的地震震级进行了对比与统计分析,发现数字记录近震的震级比远震的偏差要大,远震震级可直接与全国地震目录接轨。 相似文献
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受供电和数据传输方式的影响,十堰地震台测震系统数据断记时间较长,数据质量较差。为此,采用3路交流供电自动切换辅助2路直流供电方式,为仪器运行提供稳定的电力供给,并采用一主一备有线光纤传输解决微波单线传输的弊端。为验证解决措施的有效性,选取该台2009—2020年测震记录,统计SEED格式波形记录数据断记时长,结果发现,在2013年进行整改以来,数据断记现象减少,断记时长明显缩短。选取该台2015—2021年测震系统仪器更换以来的数据记录,分析地方震、近震、远震和极远震震相特征,发现该台记录地震波形清晰、可靠。可见,该台数据断记整改措施得到有效检验,测震系统运行质量得到提升,可为国内同类测震台站提供参考。 相似文献
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力平衡式加速度计仪器响应误差的校正方法 总被引:2,自引:2,他引:0
于海英 《地震工程与工程振动》2006,26(6):200-203
本文通过对数字强震仪系统使用的力平衡加速度计的仪器响应误差进行分析,提出了一个校正仪器响应失真的处理方法(微分-微分方法),即对未校正记录做低通滤波后运用近似理想微分器做两次微分得到校正加速度记录。针对大亚湾核电站地震仪表系统(K IS)给出了仪器校正示例,并编制了相应计算软件。该方法适用于我国强震动台网数字强震仪获取的加速度记录的仪器响应误差校正处理。 相似文献