TRG-1型潮汐重力仪摆位对标常数的影响

对六台非零位输出的TRG-1型潮汐重力仪进行摆位与标定常数的关系的实验。通过仪器对标定脉冲的响应的研究,确定各台仪器灵敏度和格值随摆位变化的关系函数。发现用变格值处理数据可以有效地消除摆位对潮汐因子测定的影响。     

长基线法和短基线法在LCR-G型重力仪格值因子标定中的应用

介绍了LCR-G型重力仪长、短基线标定格值因子的方法和过程,并对标定结果进行比较。统计了两台重力仪2008—2017年在灵山基线场标定的格值因子,分析了时序变化规律,总结了该种仪器长、短基线标定的优点、不足和适用范围。     

MINGEO-DI仪磁通门探头更换标定

因MINGEO-DI仪出现故障需更换磁通门探头,介绍探头更换、定向方法和注意事项,更换探头后计算水平角度δ、垂直角度ε,选择地磁平静时段标定格值与线性度,并经过后期观测数据对比分析,验证磁通门探头定向和性能标定的重要性和必要性。     

热带气旋对琼中台重力非潮汐变化影响研究

应用重力潮汐数据处理软件Tsoft对琼中台连续重力观测数据进行潮汐改正、零漂改正和气压改正,获取重力非潮汐变化数据;然后选取有代表性的4次台风——"纳莎"、"海燕"、"威马逊"和"海鸥",分析其登陆海南岛陆前后琼中台重力非潮汐值的变化,以研究热带气旋对琼中台重力非潮汐变化产生的影响及影响幅度。研究结果显示,热带气旋登陆海南岛陆前后,琼中台重力非潮汐变化值有所增大,其增大的幅度量级为10×10~(-8) m·s~(-2)左右,和风速、风力及台风中心与重力仪的距离相关。     

琼中台重力非潮汐变化气压与海潮负荷改正

本文对琼中台连续重力观测数据进行收集整理并处理,基于处理后的数据,进行了潮汐分析和非潮汐分析。潮汐分析采用VAV调和分析方法;非潮汐分析则分别进行了零漂改正、固体潮改正、气压改正和海潮改正。其中,零漂改正采用一般多项式拟合零漂的方法;气压改正采用VAV软件;海潮改正运用SPOTL程序,以NAO.99b潮汐模型计算了琼中台海潮负荷值。最终获得了改正后的琼中台重力非潮汐变化,结果表明琼中台的重力气压导纳值为-0.34×10^-8m/s²/mbar,气压改正幅度约为10×10^-8m/s²,海潮改正幅度约为5×10^-8m/s²。改正后,琼中台重力非潮汐变化数据,比仅进行零漂固体潮改正后的重力非潮汐变化数据中的潮汐信号更加微弱,说明进行海潮改正后的效果是明显的,该方法可进一步去除其中的潮汐信号。     

水位潮汐因子异常变化与地震活动关系的分析

研究表明,地震活动与水位潮汐因子变化有一定的关系,利用地下水静水位对潮汐应力的响应,分析了通河台1号井含水层在一些地震孕育过程中,应力变化的响应形式。运用潮汐计算模型及固体潮汐数字化观测结果,计算了固体潮汐参数,并对其潮汐变化分析出现的异常值进行了系统分析对比,总结了潮汐因子变化异常与地震的对应关系,和该井静水位潮汐变化的映震特征。结果表明,通河台潮汐异常形态对通河台附近的小震活动有较好的对应关系,讨论了通河地震台附近地震活动与水位潮汐因子异常变化的关系。     

宁夏倾斜固体潮潮汐因子熵的变化

应用宁夏银川台和石嘴山台倾斜固体潮观测数据计算了潮汐因子γ值,进一步计算了γ值的熵值,并对各熵值曲线进行分析,结果认为γ值熵在震前的异常表现比较突出,熵值变化到最低时,很有可能是应变积累到最大程度,即进入了临震状态。     

仪器标定格值变化对钻孔应变观测数据的影响

以巴南地震台钻孔应变某一时段观测资料异常变化为例,指出观测仪器元件标定格值是影响钻孔应变观测数据的重要参数,与固体潮汐幅度成反比例关系,且格值变化也可能是改变钻孔应变趋势形态的一种因素。文中分析格值与应变观测数据之间的物理机制,校正恢复异常时段观测曲线,为钻孔应变异常干扰识别工作提供参考。     

攀枝花南山地震台连续重力仪观测资料分析

选取南山地震台GS150702相对重力仪2008-01-01至2016-05-31期间的连续观测资料,对其年变化时间序列、观测值非潮汐残差曲线、M2波潮汐因子及几次地震前后的分钟观测曲线进行了分析。结果显示,南山地震台GS15重力仪器数据稳定,非潮汐观测曲线、M2波潮汐因子对几次地震都有一定的反映。     

安徽六安地震台TJ-Ⅱ体应变数据特征及异常提取方法的研究

本文对安徽市级台站六安台钻孔体应变进行了系统分析,通过对数据日常变化形态的分析,发现日变化能记录到明显的固体潮汐,但长周期数据处于"上升—开阀—上升"的数据特征;由于体应变漂移速率在缓慢改变,本文采用以月为窗长对体应变数据进行直线拟合,计算残差值,能有效消除体应变的漂移变化;通过Vendikov调和分析方法,采用以月为窗长的小时值进行潮汐计算,选取M2波振幅因子、相位滞后作为判断数据异常的依据,对本省发生的4.0级以上地震进行分析,地震前5个月未发现明显的异常。     

Accurate determination of calibration factor for tidal gravity observation of a GWR-superconducting gravimeter

Introduction The superconducting gravimeters (SGs) are widely used to observe the change in temporal and spatial gravity field by many countries along the world, considering their characteristics as of the high-precision, good continuity and stability. By using the temporal variation of the tidal grav-ity obtained from the global network of SGs, the Global Geophysics Project (GGP) aims at some hot problems in geophysics and geodynamics (SUN, HSU, 1997). The original observations of the c…     

GWR超导重力仪潮汐观测标定因子的精密测定

超导重力仪被普遍认为是迄今为止观测精度高、连续性和稳定性最好的相对重力仪，但是在获得真实重力场变化之前，必须利用格值（标定因子）对这类仪器的直接输出量（电压变化）进行标定．研究表明，格值的准确度将影响到观测数据的后续分析和资料的解释，本文利用两期（每期３天）FG５绝对重力仪在武汉国际重力潮汐基准站上的同址测量资料和该台站已知潮汐参数，详细研究了超导重力仪标定因子及其精度．      

定点地形变仪的标定问题

地形变仪器常用的标定方法可分两类:一类是间接标定法,它通过测定仪器的某几个参数而计算出仪器的格值,由于换算环节多,容易引进系统误差;另一类是直接标定法,它通过给出的一个已知物理量与仪器的输出信号对比来标定仪器的格值,此种方法精确度高,重复性强。大多数地形变仪可以用直接法标定,本文还介绍了用直接法对水平摆倾斜仪和浮子水管倾斜仪的标定。     

脉冲标定的探讨

本文应用脉冲标定原理，分析论述了电子放大地震仪所用脉冲标定方法存在的问题，提出使用降低仪器系统阻尼方法进行脉冲标定，这一方法对于脉冲标定的定性和定量研究具有现实意义。     

古地震~(14)C年龄的日历年代校正

文中简要概述了古地震14C年龄转换成日历年龄的必要性和树轮校正曲线研究历史以及当前最新研究进展,并介绍了树轮校正方法和相关校正软件,分析了日历年龄区间变宽的原因,这将有助于正确理解14C年龄及其时间标尺的内涵     

DSQ型水管仪标定计算程序

为了提高DSQ型水管倾斜仪格值标定的真实性、准确性和可靠性,根据形变学科组对仪器标定的要求编制了本程序,标定结果真实可见,标定表填写完整,格值计算快捷、准确,应用正确,提高了工作效率。     

台阵地震计程控化正弦标定系统设计

为满足台阵地震计标定要求,通过对程控化标定测控仪和标定测控软件的研究,采用一种适用于台阵地震计的程控化正弦标定方法,对中国地震局地球物理勘探中心负责管理的台阵地震计进行标定。台阵地震计标定实验结果显示,采用程控化正弦标定方法,在缩短标定时长、提高标定效率方面具有显著效果。     

石英摆标定控制电路的分析与研究

地倾斜观测精度在很大程度上取决于格值标定的准确性,本文通过利用一些简单的控制电路,使得一起标定更加准确。希望对其他有着相同仪器的台站起到一定的参考价值。     

Using model error in response history analysis to evaluate component calibration methods

This research is part of a larger effort to better understand and quantify the epistemic model uncertainty in dynamic response-history simulations. This paper focuses on how calibration methods influence model uncertainty. Structural models in earthquake engineering are typically built up from independently calibrated component models. During component calibration, engineers often use experimental component response under quasi-static loading to find parameters that minimize the error in structural response under dynamic loading. Since the calibration and the simulation environments are different, if a calibration method wants to provide optimal parameters for simulation, it has to focus on features of the component response that are important from the perspective of global structural behavior. Relevance describes how efficiently a calibration method can focus on such important features. A framework of virtual experiments and a methodology is proposed to evaluate the influence of calibration relevance on model error in simulations. The evaluation is demonstrated through a case study with buckling-restrained braced frames (BRBF). Two calibration methods are compared in the case study. The first, highly relevant calibration method is based on stiffness and hardening characteristics of braces; the second, less relevant calibration method is based on the axial force response of braces. The highly relevant calibration method consistently identified the preferable parameter sets. In contrast, the less relevant calibration method showed poor to mediocre performance. The framework and methodology presented here are not limited to BRBF. They have the potential to facilitate and systematize the improvement of component-model calibration methods for any structural system.     

Uncertainty in index flood modelling due to calibration data sizes

Regional frequency analysis is an important tool in estimating design flood for ungauged catchments. Index flood is an important component in regionalized flood formulas. In the past, many formulas have been developed based on various numbers of calibration catchments (e.g. from less than 20 to several hundred). However, there is a lack of systematic research on the model uncertainties caused by the number of calibration catchments (i.e. what is the minimum number of calibration catchment? and how should we choose the calibration catchments?). This study uses the statistical resampling technique to explore the impact of calibration catchment numbers on the index flood estimation. The study is based on 182 catchments in England and an index flood formula has been developed using the input variable selection technique in the data mining field. The formula has been used to explore the model uncertainty due to a range of calibration catchment numbers (from 15 to 130). It is found that (1) as expected, the more catchments are used in the calibration, the more reliable of the models developed are (i.e. with a narrower band of uncertainty); (2) however, poor models are still possible with a large number of calibration catchments (e.g. 130). In contrast, good models with a small number of calibration catchments are also achievable (with as low as 15 calibration catchments). This indicates that the number of calibration catchments is only one of the factors influencing the model performance. The hydrological community should explore why a smaller calibration data set could produce a better model than a large calibration data set. It is clear from this study that the information content in the calibration data set is equally if not more important than the number of calibration data. Copyright © 2011 John Wiley & Sons, Ltd.