Systematic monitoring of instrumentation health in high-density broadband seismic networks
Systematic monitoring of instrumentation health in high-density broadband seismic networks
复制标题
高密度宽带地震台网中仪器运行状况的系统监测
DOI：
10.1186/s40623-015-0226-y
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
T. Matsumoto
中科院分区：
文献类型：
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作者：
Takeshi Kimura;H. Murakami;T. Matsumoto
背景宽频带地震计数据对于地震学研究的发展是必不可少的，例如那些调查地震源和地球结构的研究。然而，以前的研究表明，描述这些数据的元数据可能会受到仪器响应错误的污染，这些错误通常难以从视觉波形检查中识别。在这里，我们报告了一个系统的方法来评估地震计条件的发展，当记录地面运动的周期范围为50至200秒的观测网络，其站间隔小于200 km.FindingsThe方法是基于在一个目标站和那些在多个周围的参考站的地震面波记录之间的比较，由此我们计算了三个指标参数，并评估了现场仪器条件，包括对输入地震动的振幅和相位响应。在我们的实验中，我们将所提出的方法应用于覆盖日本群岛的F-net宽带地震仪，其中站间隔约为100 km。这使我们能够通过计算指数参数，至少每60天评估一次每个站点的仪器健康状况。使用我们提出的方法，我们发现，大约75%的评价指标参数分布以及周围的标准值，并为大多数检查的宽带地震计，响应异常没有检测到的周期范围为50至200秒。然而，在几个台站发现了仪器误差，如在评价期间增益下降以及振幅和相位频率响应的逐渐变化（有时涉及几年）。此外，STS-1地震仪的过阻尼误差在360-s角附近经历了显著的振幅和相位频率响应变化，似乎在几个台站都很常见。相比之下，STS-2地震仪的功能更可靠，比STS-1 seismometer.ConclusionsWe开发了一种方法来评估宽带地震仪仪器条件，通过比较观测到的地震表面波在目标站与那些在多个周围的站。据信，使用我们的方法进行仪器健康的系统评估将提高地震网络的运行，并允许研究人员在进行各种数据分析之前消除受污染的数据。
BackgroundBroadband seismometer data are essential for the development of seismological studies such as those investigating earthquake sources and the Earth’s structure. However, previous studies have revealed that the metadata describing these data can possibly be contaminated by instrumentation response errors that are often difficult to recognize from visual waveform checks. Herein, we report on the development of a systematic method of assessing seismometer conditions when recording ground motions at a period range of 50 to 200 s in observation networks whose station intervals are smaller than 200 km.FindingsThe method is based on comparisons between teleseismic surface wave records at a target station and those at multiple surrounding reference stations, from which we calculate three index parameters and evaluate in situ instrumentation conditions, including amplitude and phase responses against input ground motions. In our experiments, we applied the proposed method to F-net broadband seismometers covering the Japanese Islands, where station intervals are approximately 100 km. This allows us, through calculations of the index parameters, to evaluate instrumentation health at each station at least once every 60 days. Using our proposed method, we found that approximately 75% of the evaluated index parameters distributed well around the standard values, and for most examined broadband seismometers, response anomalies are not detected at the period range of 50 to 200 s. However, instrumentation errors, such as gain decrease over the evaluated periods and gradual changes in amplitude and phase frequency responses (sometimes covering several years) were identified at a few stations. Additionally, overdamping errors at the STS-1 seismometers, which experience significant amplitude and phase frequency response variations around the 360-s corner, appear to have been common at several stations. In contrast, STS-2 seismometers appear to have functioned more reliably than STS-1 seismometers.ConclusionsWe developed a method to evaluate broadband seismometer instrument conditions by comparing teleseismic surface waves observed at a target station with those at multiple surrounding stations. It is believed that the systematic evaluation of instrumentation health using our method will enhance the operation of seismic networks, and allow researchers to eliminate contaminated data before conducting various data analyses.
H.264编码器DCT的硬件实现及其评估
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
Choong Geun Lee;V. G. Moshnyaga and K. Hashimoto;宮田康治
通讯作者：
宮田康治