Probability Data Screening Method in Airgun Signal Processing Application   总被引：1，自引：1，他引：0  

LI Jun  YOU Xiuzhen  HU Shufang 《中国地震研究》2019,33(2):235-247

The signal excited by the airgun source is weak, and is easily affected by human motion noise, instrument failure, and earthquake and blasting events, resulting in insufficient utilization of the amplitude information of the airgun signal. The effective removal of interference and the preservation of true amplitude information of the signal is difficult in airgun signal processing. Based on the randomness of noise and the highly repetitive characteristics of airgun signals, we propose probability data screening method. The airgun data from experiments conducted in the Ansha Reservoir and Shanmei Reservoir in Fujian Province in June, 2017 are taken as the research object to assess the effect in practical applications. The results show that the probability data screening method can automatically reject multiple interferences and effectively preserve the amplitude information of the signal by screening out large amplitude records in appropriate proportions. Compared with direct linear superposition, the probability-related linear superposition method can effectively reduce the impact of abnormal interference, and significantly improve the quality of the observed data.  相似文献   

山西忻州奇村水汞观测干扰因素浅析     

封丽霞  杨泽峰 《山西地震》2009,(4):37-39

为进一步明确山西忻州奇村水汞观测过程中存在的干扰因素,分别对硫酸单一试剂、综合试剂、空气湿度、同一个水样多次观测等项进行了试验。试验表明,现用硫酸及其他试剂的汞污染均不明显,对水汞观测构不成于扰;观测室内空气高湿度对水汞观测有一定干扰,且湿度越大,干扰越强,高湿度导致测值大幅突跳;通常所测的水汞含量实为在鼓泡延续时间及空气流量固定不变特定情况下的相对含量,两者的改变会对测值的可比性产生人为干扰。  相似文献   

河北三河台数字电扰动异常分析   总被引：2，自引：0，他引：2  

乔子云  张国苓  贾立峰  方召盟  刘国权  梁玉梅 《震灾防御技术》2015,10(2):426-434

从2013年12月17日开始,三河台数字电扰动观测的NS和EW两测道交替出现了背景值增大的高值异常,现场调查和分析表明,这种高值脉冲异常主要是受仪表厂的供电干扰所致,仪器本身的工作正常;对观测系统数据采集软件的数据存储格式进行研究后发现,如果出现缺数,可能造成两个测道的数据出现互换的现象,应尽快改进数据采集软件,把两个测道采集的数据改为两个数据文件;同时,模拟观测的对比结果表明,同时间段模拟观测未出现异常;通过更换东西向线路和电极,观测数据恢复正常。综合分析认为,三河台数字电扰动出现的高值异常是干扰造成的,并非震兆异常。  相似文献   

Imaging mantle transition zone thickness with SdS-SS finite-frequency sensitivity kernels     

Jesse F. Lawrence  Peter M. Shearer 《Geophysical Journal International》2008,174(1):143-158

We invert differential SdS-SS traveltime residuals measured from stacked waveforms and finite-frequency sensitivity kernels for topography on the 410- and 660-km discontinuities. This approach yields higher resolution images of transition zone thickness than previous stacking methods, which simply average/smooth over topographic features. Apparent structure measured using simple stacking is highly dependent upon the bin size of each stack. By inverting for discontinuity topography with a variety of bin sizes, we can more accurately calculate the true structure. The inverted transition zone model is similar to simple stack models with an average thickness of 242 km, but the lateral variations in thickness are larger in amplitude and smaller in scale. Fast seismic velocities in 3-D mantle models such as SB4L18 correlate with areas of thicker transition zone. The elongated curvilinear regions of thickened transition zone that occur near subduction zones are narrow and high amplitude, which suggests relatively little lateral spreading and warming of subducted lithosphere within the transition zone. The anomalously thin transition zone regions are laterally narrow, and not broadly continuous. If these variations in transition zone thickness are interpreted as thermal in nature, then this model suggests significant temperature variations on small lateral scales.  相似文献   

Numerical study of the bearing capacity for two interfering strip footings on sands     

A. Mabrouki  D. Benmeddour  R. Frank  M. Mellas 《Computers and Geotechnics》2010

Current studies of bearing capacity for shallow foundations tend to rely on the hypothesis of an isolated footing. In practice a footing is never isolated; it is mostly in interaction with other footings. This paper focuses on a numerical study using the finite-difference code Fast Lagrangian Analysis of Continua (FLAC), to evaluate the bearing capacity for two interfering strip footings, subjected to centered vertical loads with smooth and rough interfaces. The soil is modeled by an elasto-plastic model with a Mohr–Coulomb yield criterion and associative flow rule. The interference effect is estimated by efficiency factors, defined as the ratio of the bearing capacity for a single footing in the presence of the other footing to that of the single isolated footing. The efficiency factors have been computed individually to estimate the effects of cohesion, surcharge, and soil weight using Terzaghi’s equation, both in a frictional soil with surcharge pressures and in a cohesive-frictional soil with surcharge pressures. The results have been compared with those available in the literature.  相似文献   

数字化形变观测典型曲线畸变分类与说明   总被引：3，自引：1，他引：2  

黄晓华  陈智勇  林立峰 《华南地震》2008,28(4):142-148

地形变观测资料中干扰因素较多,而地震前兆与干扰往往不易区分。通过对多年地形变观测资料的整理分析,将带有普遍性干扰因素的典型畸变图像列出,并作了简要的物理机制说明．供同仁参考。  相似文献   

卫星导航信号窄带干扰抑制技术研究     

丁宇  ZHEN Wei-min  毛常波 《全球定位系统》2008,33(3):1-4

介绍了基于预测的干扰抑制技术,简述了预测滤波器工作原理及最小均方误差算法（LMS算法）,针对LMS算法的不足,给出了LMS算法改进方案并将其应用于系统仿真模型。仿真结果表明：抑制滤波器有较好的窄带干扰抑制能力,改进的LMS算法能够有效地提高系统的抗干扰能力。  相似文献   

Making Alzheimer’s disease matter. Enacting, interfering and doing politics of nature     

Ingunn Moser 《Geoforum》2008,39(1):98-110

This article contributes to recent discussions about the politics of nature by exploring how Alzheimer’s disease is being shaped as a ‘matter of concern’. Drawing on work on differences in medicine from science and technology studies, and from the geographies of naturecultures, it explores the ‘mattering’ of this disease in a number of locations including: an international Alzheimer’s patients’ movement; a medical textbook; laboratory science; daily care practice; an advertisement for anti-dementia medication; general practice; parliamentary politics; and a conference on dementia. It explores how these locations interfere and co-exist with one another and argues against the ‘science centrism’ of science and technology studies which contributes to the dominance of science and medicine by granting these analytical privilege. The same problem is posed in the recent STS turn from science to politics - the danger is that politics is similarly privileged.  相似文献   

浅析干涉与衍射的差异     

黄书辉 《广东海洋大学学报》1989,(Z1)

本文从光的传播是否遵守几何光学定律,以及解两者问题的数学工具不同、条纹分布不同等特点来分析干涉与衍射的差异。  相似文献   

山西夏县中心地震台形变山洞试记分析     

杨海祥  张文男  王向阳  王洪峰 《山西地震》2006,(3):26-30

采用水平摆倾斜仪在夏县中心地震台山洞进行了近4个月的试记,经分析得出同一构造块体上地下水位变化易引起形变记录产生畸变,而不同构造块体上地下水变化对形变记录影响甚微的结论。为夏县中心地震台洞体的掘深,实施“十五”项目做了前期准备工作,也为有关部门开展此方面工作提供了依据。  相似文献