固原体应变观测资料综合分析   总被引：1，自引：0，他引：1  

李国斌  赵卫明 《内陆地震》2011,25(1):78-84

对固原海子峡体应变2008年1月以来的观测数据进行了连续率、日漂移、内在精度以及噪声水平等方面的统计分析,结果显示观测资料连续率高,内在精度高,漂移快,噪声水平相对偏高.并从中选取了4个时段与气压进行相关分析,结果显示两者存在高度相关性,且体应变随气压变化在时间上存在40min的滞后效应,应用相关分析方法去除气压对体应...  相似文献   

高速铁路建设对宝鸡地电场观测干扰分析     

马世虎  王秋宁  李垚奇  乔波 《高原地震》2011,23(4):37-40

高速铁路（简称高铁）建设是新时期中国经济实现又好又快发展的重大战略举措。不久的将来,我国将建成遍布大江南北总进程达到16 000 km的高铁网络。地电场观测是地震前兆观测的重要手段,截止2010年,全国共建成并投入运行的地电场观测台站已经达到110个。由于高铁的设计线路与地电场观测场地难免发生＂冲突＂,因此,研究和分析...  相似文献   

检波器数量对组合压噪能力的影响   总被引：2，自引：0，他引：2  

魏继东 《物探与化探》2011,35(2):238-242

根据组合压噪的有关理论,在其他因素不变的情况下,采用数量越多的检波器,组合压制干扰波的效果越好。这使得人们认为在施工中应该采用尽量多的检波器以提高资料的信噪比。但是通过分析组合中检波器数量对规则干扰波,随机干扰波以及耦合高频微震衰减的影响证明:在其他因素不变的情况下,线性等灵敏度组合增加到"γ_max+3"个检波器以后(其中γ_max=组合基距/最小干扰波视波长), 组合对于规则干扰波的衰减能力不再随着检波器数量的增加而显著提高。在组合基距确定的情况下,检波器数量越多,对随机干扰的衰减越明显(包括在组内距小于随机干扰相关半径的情况下);但是增加到一定数量后,衰减效果不再出现明显变化。检波器数量的多少对衰减耦合高频微震没有明显作用。同时指出,确定组合中合理的检波器数量要与组合的摆放形式相结合;组合图形不合理的情况下,增加检波器数量不会显著提高组合的压噪能力;灵敏度分布不合理,是导致组合压噪能力降低的重要原因。在线性等灵敏度组合的基础上,利用玫瑰图进行分析,可以确定工区面积组合(包括道间混波后)中使用的合理的检波器数量。  相似文献   

利用信号非线性变换进行抗干扰的原理分析与电路设计     

闫守华 《成都信息工程学院学报》1997,(1)

介绍了对信号与强噪声干扰所进行的非线性变换，以实现对噪声干扰的抑制，可获得高质量的有用信号  相似文献   

日像仪的电磁干扰分析     

王威  陈志军  刘玉英  颜毅华  姬国枢 《天文研究与技术》2006,3(2):176-182

讨论了日像仪的干扰容限，列出了干扰源分布，估算出干扰测试仪灵敏度。计算了同步卫星干扰及干扰时间预测，也分析了中低轨道卫星干扰问题。对移动通信基站产生的干扰作了传播分析、计算，对脉冲雷达干扰作了谱分析及保守计算。  相似文献   

东西传播路径上JJI台站甚低频信号的日出效应研究     

王市委  倪彬彬  顾旭东  林仁桐  李光剑  罗凡  彭锐  陈欢 《地球物理学报》2022,65(1):145-156

甚低频(VLF, Very Low Frequency)波的频率范围为3~30 kHz,因其在地球-电离层波导中传播损耗小、传输距离远而被用于低电离层遥测的相关研究.本文基于武汉大学自主研发的甚低频探测系统在湖北随州(31.57°N,113.32°E)的观测数据,详细研究了中纬度地区来自日本JJI(32.04°N,130.81°E)甚低频台站信号沿东西方向传播的日出效应.在对日出期间接收信号的幅度极小值进行统计分析后发现,幅度极小值出现时间的分布与随州或JJI日出时间的变化趋势基本一致.日出期间JJI信号的幅度响应主要包括type Ⅰ和type Ⅱ两种结构,分别对应2个幅度极小值和3个幅度极小值的情况.其中,type Ⅰ结构主要发生在春夏两季,幅度极小值出现的平均时间落后随州日出时间24 min左右;type Ⅱ结构主要发生在秋冬两季.基于波模干涉理论对日出期间两种不同模式的JJI甚低频信号进行模拟研究,结果表明,在JJI-随州的东西向传播路径上,若只考虑前两阶模的影响,模拟结果与观测结果差异明显;若考虑前三阶模的影响,那么模拟结果与观测结果基本一致.由此可见,JJI甚低频信号在短路径上传播时高阶模会对信号的传播产生较大的影响,分析此类路径上甚低频台站信号的传播特征时需要考虑前三阶模甚至更高阶模的作用.  相似文献   

火焰原子吸收法测定和计算误差的减小          下载免费PDF全文

温现明  谈晶  朱朝梁  祝增虎 《盐湖研究》2002,10(2):40-46

通过对火焰原子吸收法样品分析误差产生的各主要环节的分析和实验的验证 ,指出在盐湖资源开发过程产生的混合样品分析中 ,样品稀释倍数、光谱干扰、电离干扰和计算方法是影响结果准确性的主要因素 ,进一步提出了减小误差的办法 ,并给出了用Excel处理数据的示例表格和相应的VBA程序代码。  相似文献   

Robust adaptive polarization analysis method for eliminating ground roll in 3C land seismics     

Chen Hai-Feng  Li Xiang-Yang  Qian Zhong-Ping  Zhao Gui-Ling 《应用地球物理》2013,10(3):295-304

To improve the data quality of converted waves, and better identify and suppress the strong ground-roll interference in three-component (3C) seismic recordings on land, we present an adaptive polarization filtering method, which can effectively separate the groundroll interference by combining complex polarization and instantaneous polarization analysis. The ground roll noise is characterized by elliptical plane polarization, strong energy, low apparent velocity, and low frequency. After low-pass filtering of the 3C data input within a given time-window of the ground roll, the complex covariance matrix is decomposed using the sliding time window with overlapping data and length that depends on the dominant ground-roll frequency. The ground-roll model is established using the main eigenvectors, and the ground roll is detected and identified using the instantaneous polarization area attributes and average energy constraints of the ground-roll zone. Finally, the ground roll is subtracted. The threshold of the method is stable and easy to select, and offers good groundroll detection. The method is a robust polarization filtering method. Model calculations and actual data indicate that the method can effectively identify and attenuate ground roll while preserving the effective signals.  相似文献   

A new interpretation for the interference zone between the southern Brasília belt and the central Ribeira belt,SE Brazil     

《Journal of South American Earth Sciences》2013

In southeastern Brazil, the Neoproterozoic NNW–SSE trending southern Brasília belt is apparently truncated by the ENE–WSW central Ribeira belt. Different interpretations in the literature of the transition between these two belts motivated detailed mapping and additional age dating along the contact zone. The result is a new interpretation presented in this paper. The southern Brasília belt resulted from E-W collision between the active margin of the Paranapanema paleocontinent, on the western side, now forming the Socorro-Guaxupé Nappe, with the passive margin of the São Francisco paleocontinent on the eastern side. The collision produced an east vergent nappe stack, the Andrelândia Nappe System, along the suture. At its southern extreme the Brasília belt was thought to be cut off by a shear zone, the “Rio Jaguari mylonites”, at the contact with the Embu terrane, pertaining to the Central Ribeira belt. Our detailed mapping revealed that the transition between the Socorro-Guaxupé Nappe (Brasília belt) and the Embu terrane (Ribeira belt) is not a fault but rather a gradational transition that does not strictly coincide with the Rio Jaguari mylonites. A typical Cordilleran type magmatic arc batholith of the Socorro-Guaxupé Nappe with an age of ca. 640 Ma intrudes biotite schists of the Embu terrane and the age of zircon grains from three samples of metasedimentary rocks, one to the south, one to the north and one along the mylonite zone, show a similar pattern of derivation from a Rhyacian source area with rims of 670–600 Ma interpreted as metamorphic overgrowth. We dated by LA-MC-ICPMS laser ablation (U–Pb) zircon grains from a calc-alkaline granite, the Serra do Quebra-Cangalha Batholith, located within the Embu terrane at a distance of about 40 km south of the contact with the Socorro Nappe, yielding an age of 680 ± 13 Ma. This age indicates that the Embu terrane was part of the upper plate (Socorro-Guaxupé Nappe) by this time. Detailed mapping indicates that the mylonite zone is not a plate boundary because motion along it is maximum a few tens of kilometres and the same litho-stratigraphic units are present on either side. Based on these arguments, the new interpretation is that the Embu terrane is the continuation of the Socorro-Guaxupé Nappe and therefore also part of the active margin of the Paranapanema paleocontinent. The Brasília belt is preserved even further within the central Ribeira belt than previously envisaged.  相似文献   

格尔木地震台地磁组合仪FHDZ-M15观测干扰分析     

杨广华  邱鹏成  周海生  朱胜伟 《高原地震》2012,24(3):23-25

通过对格尔木地震台地磁组合仪FHDZ-M15近5年所记录到的地磁观测资料进行各种典型干扰分析,找出仪器产生干扰的主要原因,提出对干扰的解决方法,进一步提高本台地磁观测资料质量。  相似文献