信息化时代地震观测技术的产业化问题     

周挚  山秀明  任勇  李倩  王征  郭天乐 《国际地震动态》2004,(6):8-14

国家间的竞争集中表现为前瞻性技术领域的竞争，占领技术制高点成为各国国家发展的基本取向。本文结合地震观测现状和现代信息网络技术、自动化控制技术的进展，概述了地震观测技术产业化发展的社会需求和科学需求，从国家科技发展战略层次上初步探讨了地震观测技术产业化发展的重要性和必然性。  相似文献   

2002年南海夏季风爆发期间南海北部海气通量分析与比较   总被引：4，自引：0，他引：4  

武炳义 《大气科学》2005,29(5):747-760

利用国际北极浮冰运动观测资料 (IABP)(1979～1998)以及NCEP/NCAR月平均海平面气压再分析资料(1960～2002), 通过求解海冰运动异常的复斜方差矩阵, 研究了冬季北极海冰运动主模态构成及其与海平面气压变化的关系.冬季海冰运动主模态是由两个海冰运动优势模态的一个线性组合构成, 与这两个运动优势模态有直接关系的海平面气压变化主要发生在北极海盆及其边缘海区.尽管北极涛动(北大西洋涛动)通过影响海平面气压进而影响北极海冰运动, 但是, 北极涛动(北大西洋涛动)并不是决定海冰运动主模态的关键性因素.  相似文献   

Sign-constrained robust least squares, subjective breakdown point and the effect of weights of observations on robustness   总被引：3，自引：1，他引：3  

Peiliang Xu 《Journal of Geodesy》2005,79(1-3):146-159

The findings of this paper are summarized as follows: (1) We propose a sign-constrained robust estimation method, which can tolerate 50% of data contamination and meanwhile achieve high, least-squares-comparable efficiency. Since the objective function is identical with least squares, the method may also be called sign-constrained robust least squares. An iterative version of the method has been implemented and shown to be capable of resisting against more than 50% of contamination. As a by-product, a robust estimate of scale parameter can also be obtained. Unlike the least median of squares method and repeated medians, which use a least possible number of data to derive the solution, the sign-constrained robust least squares method attempts to employ a maximum possible number of good data to derive the robust solution, and thus will not be affected by partial near multi-collinearity among part of the data or if some of the data are clustered together; (2) although M-estimates have been reported to have a breakdown point of 1/(t+1), we have shown that the weights of observations can readily deteriorate such results and bring the breakdown point of M-estimates of Huber’s type to zero. The same zero breakdown point of the L ₁-norm method is also derived, again due to the weights of observations; (3) by assuming a prior distribution for the signs of outliers, we have developed the concept of subjective breakdown point, which may be thought of as an extension of stochastic breakdown by Donoho and Huber but can be important in explaining real-life problems in Earth Sciences and image reconstruction; and finally, (4) We have shown that the least median of squares method can still break down with a single outlier, even if no highly concentrated good data nor highly concentrated outliers exist. An erratum to this article is available at .  相似文献   

川滇地区现今块体水平运动变形特征分析   总被引：2，自引：0，他引：2  

张晓亮  江在森  王双绪  陈兵  黄国柱 《地震研究》2005,28(3):262-267

依据川滇地区1991，1999和2001年GPS测量数据，利用DDA正分析基本原理，结合现有的地质资料，对该地区近年来的水平构造运动特征进行了模拟分析，认为川滇地区水平运动整体速率在1999～2001年期间明显减弱；川滇决体主压应变以顺时针旋转为主，方向为SE—SEE；其南部是运动变形相对剧烈、易于积累能量的区域；未来一两年内，该地区地震活动水平不会太高。  相似文献   

Advances in carbon flux observation and research in Asia   总被引：7，自引：0，他引：7  

YU Guirui  ZHANG Leiming  SUN Xiaomin  FU Yuling  LI Zhengquan 《中国科学D辑(英文版)》2005,48(Z1)

As an important component of FLUXNET, Asia is increasingly becoming the hotspot in global carbon research for its vast territory, complex climate type and vegetation diversity. The present three regional flux observation networks in Asia (i.e. AsiaFlux, KoFlux and ChinaFLUX)have 54 flux observation sites altogether, covering tropic rainforest, evergreen broad-leaved forest, broad-leaved and coniferous mixed forest, shrubland, grassland, alpine meadow and cropland ecosystems with a latitudinal distribution from 2°N to 63°N. Long-term and continuous fluxes of carbon dioxide, water vapor and energy between the biosphere and atmosphere are mainly measured with eddy covariance technique to (1) quantify and compare the carbon, water and energy budgets across diverse ecosystems; (2) quantify the environmental and biotic controlling mechanism on ecosystem carbon, water and energy fluxes; (3) validate the soil-vegetation-atmosphere model; and (4) serve the integrated study of terrestrial ecosystem carbon and water cycle. Over the last decades, great advancements have been made in the theory and technology of flux measurement, ecosystem flux patterns, simulation and scale conversion by Asian flux community. The establishment of ChinaFLUX has greatly filled the gap of flux observation and research in Eurasia. To further promote the flux measurement and research,accelerate data sharing and improve the data quality, it is necessary to present a methodological system of flux estimation and evaluation over complex terrain and to develop the integrated research that combines the flux measurement, stable isotope measurement, remote sensing observation and GIS technique. It also requires the establishment of the Joint Committee of Asian Flux Network in the Asia-Pacific region in order to promote the cooperation and communication of ideas and data by supporting project scientists, workshops and visiting scientists.  相似文献   

固体潮观测数据预处理中的一些常用方法     

熊先保 《地震地磁观测与研究》2005,(Z1)

从台站产出的原始地形变前兆数据出发,提出一些实际操作性较强的预处理方法,从已编制好的软件中给出处理实例,从而提高台站观测人员的科研能力,填补资料预处理方面的某些空白,这对于台站人员集观测、科研于一体有着十分重要的意义。从950102项目厦门地震台前兆数据预处理的实践表明:这些方法取得了明显的实效,直到今天仍然具有很大的使用价值。  相似文献   

Analyses on normal background characteristics about deformation observation data on the basis of wavelet transform method   总被引：1，自引：0，他引：1  

李杰  刘希强  李红  毛玉华  郑树田 《地震学报(英文版)》2005,18(1):34-42

Introduction Fourier transform that summed up a series discomposed sin functions of signal has been one of the widely used methods in the field of signal process all along. While for time information be-ing thrown away by this transform, it is difficult for us to judge when a special signal occurs on the way. Though short time Fourier transform (STFT) was developed later, which can probe local features of signals, it can not reveal what is really there because uniform window functions de-fin…  相似文献   

Detection of spheriodal free oscillation excited by Peru 8.2 M_s earthquake with five international superconducting gravimeter data     

LEI Xiang''''e  XU Houze & SUN Heping Key Laboratory of Dynamic Geodesy  Institute of Geodesy  Geophysics. Chinese Academy of Sciences  Wuhan  China Correspondence should be addressed to Lei Xiang''''e 《中国科学D辑(英文版)》2005,48(1)

In this paper, authors obtain the spectral peaks of the earth free oscillation and check all normal modes from 0S0 to 0S48 accurately, with the Fourier analysis and the maximum entropy spectrum method dealing jointly with six groups of the observational residual data from five international superconducting gravimeter stations. By comparing the observational results in this paper with three former groups of observations or models, authors notice an extra discrepancy between two observational 0S2 modes excited separately by Peru earthquake and Alaska earthquake, which probably mirrors the anisotropy of the Earth's inner core. The analysis on the splitting 1S2 mode shows that the asymmetric factor of rotationwise spectral splitting is possible to be different from that of anti-rotationwise spectral splitting.  相似文献   

自动气象站数据库资料的DLL函数输出     

张玉洁 《气象科技》2006,34(5):646-648

采用Delphi技术和Sql Server 7.0数据库开发了自动气象观测站数据库中各种气象要素的DLL(动态链接库)接口函数,建立了集雨量、温度、风向、风速、气压、湿度等各种气象要素为一体的动态链接函数库,实现了自动气象观测站数据库中各种气象要素的DLL函数输出以及各种接口函数在Delphi、VB、C 等开发环境中的调用,并且减少了用户开发过程中的重复劳动,在实际业务开发中发挥了积极作用。  相似文献   

地面观测资料同化初步研究   总被引：9，自引：0，他引：9       下载免费PDF全文

徐枝芳  龚建东  王建捷  李泽椿 《应用气象学报》2006,17(Z1):1-10

通过对比分析当前两种地面观测资料同化方案(Ruggiero方案和郭永润方案),对其优缺点进行初步分析研究。结果表明:两种同化方案同化地面观测资料后都是从模式低层到高层对分析场产生影响,中低层高度影响比较大,高层影响较小,并且对24 h模拟结果产生一定的影响。Ruggiero方案考虑了模式地形与观测站地形高度差异,但资料剔除较多,且模式分辨率越高,资料剔除对分析场的影响越明显。郭永润方案不考虑模式地形与观测站地形高度差异,假定所有地面观测资料位于模式面,因此无论模式分辨率如何,资料都能得到充分利用,但模式地形与实际观测站地形高度差异大小在地面观测资料同化分析中的影响不可忽略,因此郭永润方案有待改进,适当考虑这两种地形高度差异时效果更好。  相似文献