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Science China Earth Sciences 2005年第1期48卷 123-133页

作者： LEI Xiang'e XU Houze SUN Heping Key Laboratory of Dynamic geodesy Institute of Geodesy and Geophysics. Chinese Academy of Sciences Wuhan 430077 China Key Laboratory of Dynamic Geodesy Institute of Geodesy and Geophysics. Chinese Academy of Sciences Wuhan 430077 China Key Laboratory of Dynamic Geodesy Institute of Geodesy and Geophysics. Chinese Academy of Sciences Wuhan 430077 China

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.

关键词： 8.2 Ms Peru earthquake, detection of Earth free oscillation, observation of superconducting gravimeter,anisotropy of earth's inner core.

Towards combining multiple geophysical datasets to determine earthquake source parameters in China

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Science China Earth Sciences 2016年第11期59卷 2260-2262页

作者： ZHENG Yong LIU ChengLi State Key Laboratory of geodesy and Earth's Dynamics Institute of Geodesy and Geophysics Chinese Academy of Sciences

*** of conventional seismic studies on earthquake source parameters Earthquake source parameters,including magnitude,location,focal mechanism,rupture process are key factors for understanding seismogenic environment,mitigating seismic hazards,estimating earthquake triggering,and tectonic ***,source parameters are determined by seismological *** example,Fang L H et al.（2014）relocated the 2012 Ms6.6 Xinjiang Xinyuan earthquake sequence using local seismograms based on the double difference method,

关键词： geophysical tectonic rupture triggering magnitude estimating moderate epicenter constrain spatially

Development of German-Ukrainian cooperations for education and research in photogrammetry and laser scanning

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Geo-Spatial Information Science 2021年第1期24卷 152-159,I0016页

作者： Thomas Luhmann institute for Applied Sciences and geoinformatics Jade University of Applied Sciences OldenburgOldenburgGermany

Since 2011 an intensive international cooperation has been in place between the institute for Applied Photogrammetry and geoinformatics(IAPG)at the Jade University of Applied Sciences in Oldenburg,Germany,and various Ukrainian *** an initial contact by *** Konecny,the first visit was organized,and was followed by many *** subsequent years an intensive cooperation was established particularly with the National University for Construction and Architecture(KNUCA)in *** addition to architects and civil engineers,KNUCA also trains geodesists,geo-information scientists and landscape *** cooperation today includes the reciprocal exchange of scientists and students,research projects,courses and cooperation at many other *** addition,a commercial company has been established,SPM3D LLC,which now employs more than 14 engineers in the field of 3D acquisition,point cloud processing and *** article summarizes the history of the cooperation and presents the results of associated student *** addition,results of joint work on the development of a virtual laser scanner are presented,part of a German-Ukrainian initiative to digitize teaching.

关键词： Internationalization technology transfer curricula reform photogrammetry laser scanning e-learning

Wavelet approach to the determination of gravity tide parameters

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Science China Earth Sciences 2000年第2期43卷 158-165页

作者：柳林涛许摩泽孙和平郝兴华 Open Laboratory of Dynamic geodesy Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan China

A new approach is proposed for the determination of gravity tide parameters. Three pairs of compactly supported wavelet filters are introduced in the approach. They can efficiently extract the objective tides from the gravity observation series. The new approach guarantees a direct and precise analysis on the tidal gravity records of any sampling length. The new approach is applied to the harmonic analysis on Wuhan superconducting gravimeter records. The results clearly show the resonant effects of the Earth Nearly Diurnal Free Wobble (NDFW).

关键词： gravity wavelet filter tide parameters superconducting gravimeter.

An Efficient Approach for Historical Storage and Retrieval of Segmented Road Data in Geographic Information System for Transportation

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Chinese Geographical Science 2010年第3期20卷 236-242页

作者： Mohammad Reza Jelokhani-Niaraki Ali Asghar Alesheikh Abolghasem Sadeghi-Niaraki Faculty of geodesy and Geomatics Engineering K. N. Toosi University of TechnologyTehran Iran Department of geoinformatics Engineering Inha UniversityIncheon South Korea

One of the most powerful functions of Geographic Information System for Transportation (GIS-T) is Dynamic Segmentation (DS), which is used to increase the efficiency and precision of road management by generating segments based on attributes. The road segments describing transportation data are both spatially and temporally referenced. For a variety of transportation applications, historical road segments must be preserved. This study presents an appropriate approach to preserve and retrieve the historical road segments efficiently. In the proposed method, only the portions of segments of a time stamp that have been changed into new segments rather than storing the entire segments for every old time stamp are recorded .The storage of these portions is based on the type of changes. A recursive algorithm is developed to retrieve all segments for every old time stamp. Experimental results using real data of Tehran City, Iran justify the strength of the proposed approach in many aspects. An important achievement of the results is that database volume for 2006, 2007 and 2008 within the Historical Line Event Table (HLET) is reduced by 70%, 80% and 78%, respectively. The proposed method has the potential to prevent from vast data redundancy and the unnecessary storage of entire segments for each time stamp. Since the present technique is performed on ordinary plain tables that are readable by all GIS software, special software platforms to manage the storage and retrieval of historical segments are not needed. In addition, this method simplifies spatio-temporal queries.

关键词： GIS-T dynamic segmentation change type recursive algorithm time stamp

The nonlinear fixed gravimetric boundary value problem

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Science China Chemistry 1995年第5期38卷 596-605页

作者：于锦海朱灼文 Laboratory of Dynamical geodesy Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuchang 430077 China Laboratory of Dynamical geodesy Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuchang 430077 China)

The properly-posedness of the nonlinear fixed gravimetric boundary value problem is shown with the help of nonlinear functional analysis and a new iterative method to solve the problem is also given, where each step of the iterative program is reduced to solving one and the same kind of oblique derivative boundary value problem with the same type. Furthermore, the convergence of the iterative program is proved with Schauder estimate of elliptic differential equation.

关键词： nonlinear fixed gravimetric boundary value problem properly-posedness iterative program obliquederivative boundary vlaue problem convergence.

Rational formulation of modern geoid concept

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中国有色金属学会会刊：英文版 2011年第S3期21卷 675-680页

作者： GUO Zeng-zhang, XIAO Jian-hua geodesy institute, Henan Polytechnic University, Jiaozuo 454000, China geodesy institute Henan Polytechnic University Jiaozuo 454000 China

Based on modern geometrical field theory, a rational interpretation of modern geodesic surface concept was formulated. The general equations for geodesic surface were given. The height concept and arc length concept were formulated strictly. Their intrinsic benefits and shortages of parameter-center reference and mass-center reference systems were studied in details. The research results show that the geodesic concept depends on the available technology. The technology-dependence feature of geodesy concept was expressed by related mathematic formulations. For the satellite-based observation system, the rationality of China-2000 Geoid Reference System was explained. Discussions about how to establish regional precision reference system were made based on general equations of arc length and space distance equations. A new correction item should be taken into consideration for arc length gauge calculation.

关键词： geodesic surface parameter-center system mass-center system geodesy deformation geoid

Focal Mechanism and Rupture Process of the 2012 M_w 7.0 Santa Isabel, Mexico Earthquake Inverted by Teleseismic Data

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Journal of Earth Science 2015年第3期26卷 384-390页

作者： Chengli Liu Yong Zheng Xiong Xiong State Key Laboratory of geodesy and Earth's Dynamic Institute of Geodesy and Geophysics Chinese Academy of Sciences

The point source parameters of the April 12, 2012 Mw 7.0 Santa Isabel, Mexico, earthquake indicated by teleseismic P and SH waveforms obtained by a means of traditional cut and paste（CAP） method show that the best double-couple solution of this event is： 37°/127°, 90°/81° and-9°/-180° for strike, dip and rake, respectively. Its centroid depth is 13 km. Global teleseismic waveform data exhibit that the rupture of the earthquake initiated at a focal depth of 13 km and propagated southeastward with a relatively slow rupture velocity（about 1.8 km/s on average）. The maximum slip occurred at 30 km southeast of the hypocenter, with the peak slip of 3.57 m and total seismic moment of whole fault up to 3.98×1019 N·m. These observations provide some insight into properties, co- or post-seismic deformation and coulomb stress changes of future earthquake in this area.

关键词： Mexico Earthquake rupture velocity focal mechanism slip history

Monitoring Perennial Sub-Surface Waterlogged Croplands Based on MODIS in Jianghan Plain, Middle Reaches of the Yangtze River

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Journal of Integrative Agriculture 2014年第8期13卷 1791-1801页

作者： XIAO Fei LI Yuan-zheng DU Yun LING Feng YAN Yi FENG Qi BAN Xuan institute of geodesy and Geophysics Chinese Academy of Sciences

Perennial waterlogged soil（PWS） is induced by the high level of groundwater, and has a persistent impact on natural ecosystems and agricultural production. Traditionally, distribution information regarding PWS is mainly collected from in situ measurements through groundwater level surveys and physicochemical property analyses. However, in situ measurements of PWS are costly and time-consuming, only rough estimates of PWS areas are available in some regions. In this paper, we developed a method to monitor the perennial waterlogged cropland using time-series moderate resolution imaging spectroradiometer（MODIS） data. The Jianghan Plain, a floodplain located in the middle reaches of the Yangtze River, was selected as the study area. Temporal variations of the enhanced vegetation index（EVI）, night land surface temperature（LST）, diurnal LST differences（ΔLST）, albedo, and the apparent thermal inertia（ATI） were used to analyze the ecological and thermodynamic characteristics of the waterlogged croplands. To obtain pure remote sensing signatures of the waterlogged cropland from mixed pixels, the croplands were classified into different types according to soil and land cover types in this paper, and a linear mixing model was developed by fitting the signatures using the multiple linear regression approach. Afterwards, another linear spectral mixing model was used to get the proportions of waterlogged croplands in each 1 km×1 km pixel. The result showed an acceptable accuracy with a root-mean-square error of 0.093. As a tentative method, the procedure described in this paper works efficiently as a method to monitor the spatial patterns of perennial sub-surface waterlogged croplands at a wide scale.

关键词： perennial waterlogged soil waterlogging MODIS enhanced vegetation index

Evaluation of spatial-temporal dynamics in surface water temperature of Qinghai Lake from 2001 to 2010 by using MODIS data

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Journal of Arid Land 2013年第4期5卷 452-464页

作者： Fei XIAO Feng LING Yun DU Qi FENG Yi YAN Hui CHEN institute of geodesy and Geophysics Chinese Academy of Sciences

Lake surface water temperature （SWT） is an important indicator of lake state relative to its water chemistry and aquatic ecosystem,in addition to being an important regional climate ***,few literatures involving spatial-temporal changes of lake SWT in the Qinghai-Tibet Plateau,including Qinghai Lake,are *** objective is to study the spatial-temporal changes in SWT of Qinghai Lake from 2001 to 2010,using Moderate-resolution Imaging Spectroradiometer （MODIS） *** on each pixel,we calculated the temporal SWT variations and long-term trends,compared the spatial patterns of annual average SWT in different years,and mapped and analyzed the seasonal cycles of the spatial patterns of *** results revealed that the differences between the average daily SWT and air temperature during the temperature decreasing phase were relatively larger than those during the temperature increasing *** increasing rate of the annual average SWT during the study period was about 0.01℃/a,followed by an increasing rate of about 0.05℃/a in annual average air *** annual average SWT from 2001 to 2010 showed similar spatial patterns,while the SWT spatial changes from January to December demonstrated an interesting seasonal reversion *** high-temperature area transformed stepwise from the south to the north regions and then back to the south region from January to December,whereas the low-temperature area demonstrated a reversed annual cyclical *** spatial-temporal patterns of SWTs were shaped by the topography of the lake basin and the distribution of drainages.

关键词： surface water temperature (SWT) spatial-temporal changes MODIS Qinghai Lake