2000国家GPS大地控制网数据处理方法与结果   总被引：9，自引：2，他引：7  

唐颖哲  杨元喜  宋小勇 《大地测量与地球动力学》2003,23(3):77-82

介绍了我国GPS大地控制网的基本情况,阐述了结合地壳运动观测网络工程建立全国统一的“2000国家GPS大地控制网”的意义,并介绍了整网平差中采用的技术方法和最后平差结果及精度。  相似文献   

Extensions to Spatial Factor Methods with an Illustration in Geochemistry     

T. C. Bailey  W. J. Krzanowski 《Mathematical Geology》2000,32(6):657-682

Many applications involving spatial data require several layers of information to be simultaneously analyzed in relation to underlying geography and topographic detail. This in turn generates a need for forms of multivariate analysis particularly oriented to spatial problems and designed to handle spatial structure and dependency both within and between spatially indexed multivariate responses. In this paper we focus on one group of such methods sometimes referred to as spatial factor analysis. Use of these techniques has so far been mostly restricted to applications in the geosciences and in some forms of image processing, but the methods have potential for wider use outside these fields. They are concerned with identifying components of a multivariate data set with a spatial covariance structure that predominantly acts over a particular spatial range or zone of influence. We review the various forms of spatial factor analysis that have been proposed and emphasize links between them and with the linear model of coregionalization employed in geostatistics. We then introduce extensions to such methods that may prove useful in exploratory spatial analysis, both generally and more specifically in the context of multivariate spatial prediction. Application of our proposed exploratory techniques is demonstrated on a small but illustrative geochemical data set involving multielement measurements from stream sediments.  相似文献   

Short and long memory unobserved components in hydrological time series     

Marcella Corduas  Domenico Piccolo 《Physics and Chemistry of the Earth》2006,31(18):1099-1106

In this paper a semiparametric approach is introduced to decompose an ARFIMA model in the long memory and short memory unobserved components. The procedure is based on the DECOMEL method which produces a statistical decomposition by minimizing the Euclidean distance between the spectrum of the aggregated series and the sum of the parametric spectra of the components. The extension to long memory stationary models is achieved defining an approximate model where the fractional operator is replaced by the ratio of two polynomials of order one. The feasibility and performance of the proposed procedure are discussed through a case study.  相似文献   

Seismic Moment Tensor Resolution on a Local Scale: Simulated Rockburst and Mine-induced Seismic Events in the Kopanang Gold Mine, South Africa   总被引：2，自引：0，他引：2  

Jan Šílený  Alexander Milev 《Pure and Applied Geophysics》2006,163(8):1495-1513

Seismic records contain information about the effect of the source as well as the effect of wave propagation through the rock mass. The effect of wave propagation is usually not well known as only simplified models of geological structures are available. Therefore, the information about the source retrieved by inverting seismograms may include errors due to incomplete knowledge of the rock mass along the propagation path, which in turn cause a distortion in the calculated moment tensor (MT). The distortion of the MT on a local scale was observed by inverting records of a simulated rockburst conducted at the Kopanang gold mine in South Africa. A dominant isotropic component of the explosive characteristics was found from the inversion. The deviatoric components retrieved from the blast are spurious. A test of their stability indicated that they are not significant, assuming an uncertainty above 5% for velocities and 10% for attenuation within the homogeneous model available for the mine. Thus, the retrieval of the MT from records of local networks in mines using a homogeneous model of the rock mass seems to be feasible. However, the homogeneous model of the rock mass can only be applied to close stations, within a few kilometers of the source. The seismic records from distant stations were too complex to be modelled by a homogeneous rock mass. Records of six mine-induced seismic events recorded at the Kopanang gold mine were also inverted. A vertical linear dipole along the pressure (P) axis was found for three of the events, suggesting a pillar burst. The mechanism of two events contains an isotropic implosion together with a nearly vertical dip-slip, and seems to indicate a combination of a cavity collapse with a down dip-slip along a nearly vertical fault. One event corresponds to a dipole along the tensional (T) axis. However, it is vertical, thus its association with tensile faulting of the hangingwall is uncertain.  相似文献   

基于虚拟观测的病态问题解法   总被引：2，自引：0，他引：2  

冯光财  戴吾蛟  朱建军  陈正阳 《测绘科学》2007,32(2):38-39,66

在大地测量数据处理领域中,处理病态问题的主要方法有:岭估计方法、奇异值分解法(SVD)、Tik-honov正则化方法等,但是这些方法大多数是强调数学上的意义,没有充分联系大地测量的实际情况,因此不利于在测绘领域病态问题本质的理解和研究。为使病态问题的求解具有实际的物理意义,提出了基于虚拟观测的岭估计方法。该方法将先验约束条件作为一类互相独立的虚拟观测值,从而把病态问题转化为测量平差问题,然后运用Helmert方差估计法来确定岭参数。该方法还可以得到的参数之间的权矩阵,用它来代替虚拟观测值的权矩阵,重新对参数进行计算,则实现了该方法向广义岭估计的推广。实际算例分析的结果表明该方法不仅计算简单而且能保证结果精确。  相似文献   

基于MATLAB COM组件的变形监测与分析软件开发     

刘晓俭  邹进贵  熊川 《地理空间信息》2007,5(3):96-99

论述了桥梁变形自动监测系统数据的频谱分析以及小波分析方法,并利用MATLAB编译的COM组件,实现了在VC中调用该COM组件以实现脱离MATLAB环境的变形分析软件开发。  相似文献   

建筑抗震构件中屈曲约束支撑结构研究新进展          下载免费PDF全文

陈剑波  完海鹰 《地震工程学报》2020,42(5):1289-1302

详细介绍了近年来中国学者在屈曲约束支撑研究方面取得的研究成果，着重讨论了屈曲约束支撑构件（核心单元、约束机构、无黏结构造层）和整体抗震性能以及设计方法的研究现状。结果表明：屈曲约束支撑以其良好的耗能性能具有很好的发展潜力，屈曲约束支撑的适用范围不断拓展，结构形式更趋多样化，设计方法不断优化。  相似文献   

中朝边境地区新生代火山岩系对比     

曹林  金伯禄  朱东 《吉林大学学报(地球科学版)》1998,(2)

通过对比中国长白山区和朝鲜白头山区新生代火山岩系的层序和同位素年代学资料,首次编制出中朝边境地区新生代火山岩系分布图和新生代火山喷发阶段对比表。其岩石化学和地球化学演化趋势表明,该区新生代火山完全有可能再次喷发。  相似文献   

Multivariate correlation analysis of suspended-sediment characteristics     

Satoshi Yamamoto 《Mathematical Geology》1976,8(1):57-74

Principal component analysis (PCA) was employed to investigate interrelationships among various characteristics of seawater and suspended sediments obtained from surface waters of two Asian marginal seas. On the basis of multivariate correlation analysis for the two marginal seas combined, three important factors were extracted and interpreted: (1) current-energy conditions, (2) the influence of rivers, and (3) biochemical conditions of seawater. A relationship between anisotropic mineral grains and combustible organic matter is suggested by the fact that suspended sediment, containing coarser anisotropic mineral grains, also contains larger amounts of combustible organic matter.  相似文献   

An effect of closure on the structure of principal components   总被引：2，自引：0，他引：2  

Felix Chayes  Jürgen Trochimczyk 《Mathematical Geology》1978,10(4):323-333

The principal components transformation generates, from any data array, a new set of variables—the scores of the components—characterized by a total variance exactly equal to that of the initial set. It is in this sense that the transformed variables are said to contain, preserve, or account for, the variance of the original set. The scores, however, are uncorrelated. In the course of the transformation, what becomes of the strong interdependence of variance and covariance so characteristic of closed arrays? The question seems to have attracted little attention; we are aware of no study of it in the earth sciences. Experimental work reported here shows quite clearly that the overall equivalence of variance and covariance imposed by closure, though absent from the component scores,may emerge in relations between the coefficientsof each of the lower-order components; if the raw data are complete rock analyses, the sum of all the covariances of the coefficients of such a component is negative, and is very nearly equal to the sum of all the variances in absolute value. (In all cases so far examined, the absolute value of the first sum is a little less than that of the second.) The principal components transformation provides an elegant escape from closure correlation if a petrographic problem can be restated entirely in terms of component scores, but not if a physical interpretation of the component vectors is required.  相似文献