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A comparative study on 3-D solar wind structure observed by Ulysses and MHD simulation

Science Bulletin 2005年第07期50卷 672-678页

作者： FENG Xueshang, XIANG Changqing, ZHONG Dingkun & FAN Quanlin SIGMA Weather Group, key laboratory of Space Weather key Labo- ratory of Geospace Environment and geodesy, Ministry of Education, Center for Space Science and Applied Research, chinese academy of sciences, Beijing 100080, China SIGMA Weather Group Key Laboratory of Space Weather Key Labo- ratory of Geospace Environment and Geodesy Ministry of Education Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China

During Ulysses’ first rapid pole-to-pole transit from September 1994 to June 1995, its observations showed that middle- or high-speed solar winds covered all latitudes except those between ?2.° and +2.° near the ecliptic plane, where the velocity was 300―450 km/s. At poleward 40°, however, only fast solar winds at the speed of 700―870 km/s were observed. In addition, the transitions from low-speed wind to high-speed wind or vice versa were abrupt. In this paper, the large-scale structure of solar wind observed by Ulysses near solar minimum is simulated by using the three-dimensional numerical MHD model. The model com- bines TVD Lax-Friedrich scheme and MacCormack II scheme and decomposes the calculation region into two re- gions: one from 1 to 2. Rs and the other from 18 Rs to 1 AU. Based on the observations of the solar photospheric magnetic field and an addition of the volumetric heating to MHD equations, the large-scale solar wind structure mentioned above is reproduced by using the three-dimensional MHD model and the numerical results are roughly consistent with Ulysses’ observations. Our simulation shows that the initial magnetic field topology and the addition of volume heating may govern the bimodal structure of solar wind observed by Ulysses and also demonstrates that the three-dimensional MHD numerical model used here is efficient in modeling the large-scale solar wind structure.

关键词： Ulysses observation solar wind structure numerical simulation.

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SATELLITE GRAVITY SURVEYING TECHNOLOGY AND RESEARCH OF EARTH’S GRAVITY FIELD

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大地测量与地球动力学 2003年第B12期23卷 1-7页

作者： Ning Jinsheng (The key laboratory of Geo Space Environment and {2., Ministry of Education, wuhan University, wuhan 430079, China) The key laboratory of Geo-Space Environment and {2. Ministry of EducationWuhan University Wuhan 430079 China

This is a summarized paper. Two topics are discussed: Firstly, the concept, development and application of four kinds of satellite gravity surveying technology are introduced; Secondly, some problems of theory and method, which must be considered in the study of the \{Earth’s\} gravity field based on satellite gravity data, are expounded.

关键词：卫星重力测量技术地球重力场卫星轨道技术概念技术进展技术应用空中重力测量

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Estimation on principal component of multi-collinearity Gauss-Markov model based on minimum description length

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中国有色金属学会会刊：英文版 2005年第S1期15卷 153-155页

作者： SHI Yu-feng~(1, 2. (1. Shandong University of Technology, Zibo 2.5049, China 2. key laboratory of Geospace Environment and {2., Ministry of Education, wuhan University, wuhan 430079, China) Shandong Univ Technol Zibo 255049 Peoples R China wuhan Univ Minist Educ Key Lab Geospace Environm & Geodesy Wuhan 430079 Peoples R China

Gauss-Markov model is frequently used in data analysis; the analysis and estimation of its parameters is always a hot issue. Based on the information theory and from the viewpoint of optimal information on description—minimum description length, this paper discusses a case: where there is multi-collinearity in the coefficient matrix, principal component estimation is used to estimate and select the original parameters, so as to reduce its multi-collinearity and improve its credibility. From the viewpoint of minimum description length, this paper discusses the approach of selecting principal components and uses this approach to solve a practical problem.

关键词： minimum description length Gauss-Markov model multi-collinearity principal component estimation

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模拟研究卫-卫跟踪中星间隔的选择问题

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天文学报 2005年第1期46卷 62-69页

作者：周旭华吴斌许厚泽彭碧波中国科学院测量与地球物理研究所动力大地测量重点实验室

从两个方面讨论了低轨卫星在做卫-卫跟踪(SST)观测时,星间隔的选择问题. 1)用地球重力位系数作为扰动量,比较该扰动引起的不同间隔的SST星间距离和速度变化大小. 2.用随机误差为1μm／s的星间速度变化作为模拟观测量,恢复不同间隔的 ... 详细信息

从两个方面讨论了低轨卫星在做卫-卫跟踪(SST)观测时,星间隔的选择问题. 1)用地球重力位系数作为扰动量,比较该扰动引起的不同间隔的SST星间距离和速度变化大小. 2.用随机误差为1μm／s的星间速度变化作为模拟观测量,恢复不同间隔的地球重力位系数,并做精度评估.两种结果表明,适当增大SST间隔对求解重力场有利, 但无限制增大无实际意义,对于选定高度为42. km卫星,在作SST观测时,星间隔不宜超过690km.此模拟方法及结果对我国确定重力卫星指标有着重要意义.

关键词： SST 重力位地球模拟观测重力卫星重力场低轨卫星间隔扰动系数

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Progress in technology for the 2.05 height determination of Qomolangma Feng (Mt. Everest)

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Science China Earth sciences 2006年第5期49卷 531-538页

作者： CHEN Junyong1,2. YUAN Janli1,2. GUO Chunxi1,2. ZHANG Yanping1 & ZHANG Peng1,2.1. State Bureau of Surveying and Mapping, Beijing 100830, China 2. School of geodesy and Geomatics, wuhan University, wuhan 430079, China 1. State Bureau of Surveying and Mapping Beijing 100830 China 2. School of geodesy and Geomatics Wuhan University Wuhan 430079 China

In 2.05 China carried out a new geodetic campaign for the height determination of Qo- molangma Feng——Mt. Everest (QF in short). The technical progresses in geodesy for the 2.05 campaign are presented in the paper. GPS positioning was the key technique in the campaign. After summarizing the experiences and lessons of the GPS positioning on the QF summit in the previous QF height determination campaigns, some measures were taken to raise the accuracy and reliability of the height determination with GPS techniques. In order to raise the accuracy of the height deter- mination of the QF summit with classical geodetic techniques, laser ranging was used together with the trigonometric levelling in the 2.05 campaign. It is the first time in China the thickness of the ice-snow layer on the QF summit was measured by ground penetrating radar integrated with GPS. The local gravity field and geoid in the QF area was improved on the basis of earth gravity field model integrated with new ground gravity data, DTM data and GPS leveling data in the QF area. In the 2.05 campaign the normal height and orthometric height (height above sea level) of the snow surface of the QF summit were obtained as 8846.67 m and 8847.93 m respectively. The orthometric height of the rock surface of the QF summit is 8844.43 m,and the thickness of the ice-snow layer on the QF summit is 3.50 m.

关键词： Qomolangma Feng, Mt. Everest, height determination, GPS, gravity field, ground penetrating radar.

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Partial continuation model and its application in mitigating systematic errors of double-differenced GPS measurements

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Progress in Natural Science:Materials International 2005年第3期 54-59页

作者： GUO Jianfeng 1,2.ˇˇ ,OU Jikun 1 and REN Chao 1 (1.key laboratory of Geo{2.s,institute of geodesy and geophysics,chinese academy of sciences,wuhan430077,China 2.Graduate School of the chinese academy of sciences,Beijing100039,China) key laboratory of Geo{2.s，institute of geodesy and geophysics，chinese academy of sciences，wuhan 430077，China Graduate School of the chinese academy of sciences，Beijing 100039，China key laboratory of Geo{2.s，institute of geodesy and geophysics，chinese academy of sciences，wuhan 430077，China

Based on the so-called partial continuation model with exact finite measurements,a new stochastic assessment procedure is *** every satellite pair,the temporal correlation coefficient is estimated using the original double-differenced(DD)GPS *** then,the Durbin-Watson test is applied to test specific hypothesis on the temporal correlation *** the test is not significant with a certain significant level,a data transformation is *** transformed measurements are free of time *** purpose of illustration,two static GPS baseline data sets are analyzed in *** experimental results demonstrate that the proposed procedure can mitigate effectively the impact of systematic errors on DD GPS measurements.

关键词： partial continuation model systematic errors GPS double-differenced measurements.

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An efficient rendering method for large vector data on large terrain models

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Science China(Information sciences) 2010年第6期53卷 1122-1129页

作者： YANG Ling1,ZHANG LiQiang1,KANG ZhiZhong2.XIAO ZhiQiang1,PENG JunHuan2.ZHANG XingMing1 & LIU Liu11State key laboratory of Remote Sensing Science,Jointly Sponsored by Beijing Normal University and the {2. of Remote Sensing Applications of chinese academy of sciences,Beijing 100875,China 2.epartment of geodesy and Geomatics,School of Land Science and Technology,China University of Geosciences,Beijing 100083,China 1. State key laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and the Institute of Remote Sensing Applications of Chinese Academy of Sciences Beijing 100875 China2. Department of Geodesy and Geomatics School of Land Science and Technology China University of Geosciences Beijing 100083 China

This paper presents an efficient way to render large-scale vector maps on level-of-detail(LOD) digital elevation models(DEMs).By using the frame buffer and Voronoi diagram,we achieve a rapid simplification of large-scale vector maps while keeping their original topological *** the simplified maps,we establish level-of-detail vector map *** the detailed level,we use the stencil shadow volume approach to render the map accurately,and in the coarse level we use substitute techniques to render the map approximately yet more *** method proposed in this paper is universally applicable to rendering vector maps on various LOD terrain models,and the overlaying performance is independent of the complexity of underlying terrain *** use of the view frustum culling and sub-region index techniques,the impact of complexity of vector maps is reduced,and the rendering time is restricted to a certain ***,we can achieve seamless and rapid rendering of large-scale vector maps on LOD terrain surfaces.

关键词： large-scale vector maps LODs view-dependent visualization

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时间序列数字滤波后自由度的确定——应用于日长变化与南方涛动指数的相关分析

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天文学报 2003年第3期44卷 324-329页

作者：闫昊明钟敏朱耀仲中国科学院测量与地球物理研究所动力大地测量学重点实验室武汉430077

原始观测时间序列进行数字滤波后,其自由度将大大降低。对各种数字滤波器都可以通过 Monte Carlo方法模拟获得对应置信水平的相关系数临界值,从而得到时间序列滤波后的自由度。如果滤波后的频段宽度与Nyquist频率之比为Z,那么对于理想... 详细信息

原始观测时间序列进行数字滤波后,其自由度将大大降低。对各种数字滤波器都可以通过 Monte Carlo方法模拟获得对应置信水平的相关系数临界值,从而得到时间序列滤波后的自由度。如果滤波后的频段宽度与Nyquist频率之比为Z,那么对于理想的单边和双边滤波器,时间序列滤波后的自由度为原始值的Z/2.Z倍,非理想滤波器一般不符合此规律。

关键词：数字滤波天体测量学日长变化南方涛动指数 MonteCarlo方法

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Contemporary crustal movement of continental China obtained by global positioning system(GPS) measurements

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chinese Science Bulletin 2001年第18期46卷 1552-1554,1588页

作者： MA Zongjin, CHEN Xinlian, YE Shuhua, LAI Xian, WEI Ziqing, CHEN Junrong, NING Jinsheng, XU Huoze & DING Guoyu1. Insitute of Geology, China Seismological Bureau, Beijing 10002., China (e-mail: disgroup@***)2. Center for Analysis and Prediction, China Seismological Bureau, Beijing 100036, China 3. Shanghai Astronomic Observatory, chinese academy of sciences, Shanghai 2.0030, China 4. institute of Seismology, China Seismological Bureau, {2. 430077, China 5. institute of Survey and Mapping, Xi’an 710054, China 6. National Bureau of Survey and Mapping, Beijing 100830, China 7. {2. University, {2. 430077, China 8. institute of geodesy and geophysics, {2. 430077, China 9. China Seismological Bureau, Beijing 100036, China Insitute of Geology China Seismological Bureau Beijing China Center for Analysis and Prediction China Seismological Bureau Beijing China Shanghai Astronomic Observatory Chinese Academy of Sciences Shanghai China institute of Seismology China Seismological Bureau Wuhan China institute of Survey and Mapping Xi’an China National Bureau of Survey and Mapping Beijing China wuhan University Wuhan China institute of geodesy and {2. Wuhan China China Seismological Bureau Beijing China

We obtain a unified horizontal velocity field of continental China and vicinity through measurements at 81 GPS stations provided by the National key Infrastructure Project, Crustal Movement Observation Network of China. The velocity field delineates patterns of movements and deformation of active crustal blocks in continental China under the Eurasia-fixed reference frame. The space-based geodesy also clearly shows for the first time the horizontal movementand deformation of continental China induced by indentation of the Indian plate. The data provide kinematic constraints for simulating {2. process of continental litho-spheric deformation.

关键词： crustal movement velocity field tectonic deformation.

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Influence of the density and thickness variation of the lithosphere on the parameters of NNR-NUVEL plate model:a preliminary study

Influence of the density and thickness variation of the lith...

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中国地球物理学会第二十七届年会

作者： WenBin Shen~(1,2.) Rong Sun~1 1.Dept.of geophysics,School of geodesy and Geomatics,{2. University,{2. 430079,China 2.key Lab.of Geospace Environment and geodesy,{2. University,{2. 430079,China

＜正＞*** Plate models given by geological studies describe the relative motion of one plate with respect to other ***,there are many plate models available,like NUVEL,PB2.02.and ***,a plate model may be described by its geometric figure and rotation *** describe the relative motion of the plates to the underneath asthenosphere,additional requirements are *** frequently used is the no net rotation （NNR） requirement which assumes that the net angular momentum of the lithosphere is *** this frame,the inertia moments of each plate is obtained by calculating the surface integration on the surface of a unit sphere since the density and thickness of the lithosphere is considered to be invariant with respect to ***

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