检索结果-南通市图书馆

Long term monitoring of urban subsidence by Permanent Scatterer DInSAR

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第1期17卷 107-111页

作者： TANG Yixian, ZHANG Hong and WANG Chao ( The Chinese remote {1. Satellite Ground Station, Chinese Academy of Sciences, Beijing 1.0086, china State Key Laboratory of remote {1. IRSA, Chinese Academy of Sciences, Beijing 1.01.1. china) Chinese remote {1. Satellite Ground Station Chinese Academy of Sciences Beijing 100086 China State Key Laboratory of remote {1. IRSA Chinese Academy of Sciences Beijing 100101 China

When using differential SAR interferometry (DInSAR) to monitor the surface deformation over a long time scale, it is often strongly affected by the spatial and temporal decorrelations and atmospheric dishomogeneities. The recently developed Permanent Scatterers (PS) technique proposed by Fertti et al. can overcome these difficulties by interpreting time-series of interferometric phase only at coherent point scatterers. In this study, we apply this PS technique using 25 ERS-1.2 scenes from 1.92 to 2000 to monitor the subsidence in Suzhou. By using the linear deformation model, the deformation map in Suzhou urban area over the eight years is obtained. And the calculated results are in good agreement with the measurements of leveling.

关键词： Permanent Scatterer differential SAR interferometry urban subsidence.

Framework and development of digital china

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2008年第S1期51卷 1-5页

作者： WU Lun & TONG QingXi Institute of remote {1. and Geographical Information Systems,Peking University,Beijing 1.0871.china Institute of remote {1. and Geographical Information Systems Peking University Beijing China

Digital china (DC) has recently drawn much attention. It is a strategic project for china in response to the challenge of sustainable development of population,re-source,and environment. Intending to establish the national information infra-structure (NⅡ),the DC project forms a solid foundation for Chinese informatization. In such an NⅡ,multi-sourced spatial data are integrated. They focus on various themes and have different space and time features. Based on the NⅡ,numerous applications and services can be developed so that spatial information will benefit everyone. Since lots of organizations,such as governments,universities,and en-terprises,are involved in the implementation of DC,the DC project will significantly prompt the relevant scientific research as well as economic progress in china.

关键词： Digital Earth Digital china spatial information sciences and technology

Matrix calculation of high-dimensional cross product and its application in automatic recognition of the endmembers of hyperspectral imagary

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第1期54卷 197-203页

作者： GENG XiuRui1.ZHAO YongChao1.LIU SuHong2 & WANG FuXiang3.1.ey Laboratory of Technology in Geo-spatial Information Processing and Application System, Institute of Electronics,Chinese Academy of Sciences,Beijing 1.0080,{1. 2State Key Laboratory of remote sensing Science,Jointly Sponsored by Beijing Normal University and the Institute of remote sensing Applications of Chinese Academy of Sciences, School of Geography,Beijing Normal University,Beijing 1.0875,{1. 3.chool of Electronics and Information Engineering,Beihang University,Beijing 1.01.1.{1. Key Laboratory of Technology in Geo-spatial Information Processing and Application System Institute of Electronics Chinese Academy of Sciences Beijing China State Key Laboratory of remote {1. Science Jointly Sponsored by Beijing Normal University and the Institute of remote {1. Applications of Chinese Academy of Sciences School of Geography Beijing Normal University Beijing China School of Electronics and Information Engineering Beihang University Beijing China

This paper gives the definition of the high-dimensional cross product and its calculation by extending the 3.D cross product definition into the high-dimensional vector *** on the properties of the cross product,the volume variance index(VVI)is proposed to be used in extracting automatically the endmembers of the hypherspectral imagery which eliminates the shortcoming of the traditional method of using simplex only where the extraction results were easily impacted by the abnormal pixels.A case study of endmembers extraction experiment using the VVI method with the AVIRIS data for Cuprite has shown a very good result.

关键词： endmember simplex hyperspectral imagery cross product

Physico-Chemical Properties and Laboratory Hyperspectral Reflectance of Coastal Saline Soil in Shangyu City of Zhejiang Province, china

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2003年第3期13卷 193-198页

作者： SHI ZHOU, HUANG MINGXIANG and LI YANInstitute of Agricultural remote {1. and Information System, Zhejiang University, Hangzhou 3.0029 (china) Institute of Agricultural remote {1. and Information System Zhejiang University Hanyzhou 310029

45 and 50 composite soil samples were collected, respectively, from twoagricultural fields, that were enclosed and reclaimed from coastal tidal-flat areas in 1.96 and 1.84respectively, in Shangyu of Zhejiang Province, china, to investigate the physico-chemicalproperties and the hyperspectral characteristics of the saline soils and to make an assessment ontheir relationships. The reflectance spectra of saline soils were measured using a spectroradiometerin laboratory. The mean spectral curves of the saline soils from the two sites different inreclamation year showed that the saline soil taken from the recently reclaimed land with highersalinity demonstrated a lower reflectance intensity in the spectral region from about 550 nm to 2{1.0nm. In addition, nine absorption bands, i.e., 488 nm, 5{1. nm, 670 nm, 880 nm, 940 nm, 1.00 nm, 1.00nm, 2 200 nm and 2 {1.0 nm, were chosen as the spectral bands to investigate the relationshipsbetween soil physico-chemical properties by means of Pearson correlation analysis. Finally, thefirst two principal components were calculated from nine absorption bands and used to discriminatethe saline soil samples taken from two sampled fields. The results indicate that it is feasible todetect physico-chemical properties of saline soils from fields reclaimed for varying time periods onthe basis of the hyperspectral data.

关键词： coast hyperspectral reclamation saline soils

Fuzzy entropy image segmentation based on particle swarm optimization

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2008年第9期18卷 1167-1171页

作者： Linyi Li a, Deren Li b, a School of remote {1. and Information Engineering, Wuhan University, Wuhan 43.079, china b State Key Laboratory of Information Engineering in Surveying, Mapping and remote {1., Wuhan University, Wuhan 43.079, china School of remote {1. and Information Engineering Wuhan University Wuhan 430079 China State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China

Particle swarm optimization is a stochastic global optimization algorithm that is based on swarm *** of its excellent performance, particle swarm optimization is introduced into fuzzy entropy image segmentation to select the optimal fuzzy parameter combination and fuzzy threshold *** this study, the particles in the swarm are constructed and the swarm search strategy is proposed to meet the needs of the segmentation *** fuzzy entropy image segmentation based on particle swarm opti-mization is implemented and the proposed method obtains satisfactory results in the segmentation *** with the exhaustive search method, particle swarm optimization can give the same optimal fuzzy parameter combination and fuzzy threshold while needing less search time in the segmentation experiments and also has good search stability in the repeated ***, fuzzy entropy image segmentation based on particle swarm optimization is an eficient and promising segmentation method.

关键词： Image segmentation Fuzzy entropy Particle swarm optimization Fuzzy parameter combinations Fuzzy threshold

Potential land for plantation of Jatropha curcas as feedstocks for biodiesel in china

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2010年第1期53卷 120-127页

作者： WU WeiGuang 1.2,3.HUANG JiKun 1.3.& DENG XiangZheng 1.3.1.Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 1.01.1.china 2 Department of Economics and Management,Zhejiang Forestry University,Linan 3.1.0}0,china 3.center for Chinese Agricultural Policy,Chinese Academy of Sciences,Beijing 1.01.1.china Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Department of Economics and Management Zhejiang Forestry University Linan China center for Chinese Agricultural Policy Chinese Academy of Sciences Beijing China

As a renewable energy,biofuel has attracted great attention in china and the rest of *** with the national food security,china recently has shifted its biofuel development priority from grain-based to non-grain-based biofuels,including forest-based biodiesel,since *** curcas is one of major biodiesel ***,there is rising debate on availability of land for expanding Jatropha curcas *** overall goal of this paper is to evaluate potential land for Jatropha curcas used as feedstock for biodiesel in *** on remote {3. data on land use,data on meteorological,soil and land slope,and suitable environment for Jatropha curcas plantation,this study uses Agro Ecological Zone method and considers social-economic constraints to evaluate potential suitable land for Jatropha curcas plantation in china's major Jatropha curcas production region,Southwest *** results show that while there are some potential lands to expand Jatropha curcas areas,amount of these lands will hardly meet the government's target for Jatropha curcas-based biodiesels development in the *** may need to reconsider its long-term targets on the development of Jatropha curcas-based biodiesels.

关键词： biodiesel Jatropha curcas potential land suitability evaluation Southwest china

Soil erosion in china based on the 2000 national {1. sensing survey

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2002年第4期12卷 435-442页

作者： XU Feng1.2, GUO Suoyan2, ZHANG Zengxiang1.1. Institute of remote {1. Applications, CAS, Beijing 1.01.1. china 2. Monitoring {3. of Soil and Water Conservation, Ministry of Water Resources, Beijing 1.0053. china) Institute of remote {1. Applications CAS Beijing China Monitoring center of Soil and Water Conservation Ministry of Water Resources Beijing China

This paper discussed the spatial distribution of soil erosion in china at the end of the 20th century based on the second national soil erosion survey. The result indicated soil erosion is still the prime environmental problem in china. Soil erosion mainly occurs in the western regions of china, and the slight erosion type, ion the whole, exerts the greatest impact on soil erosion pattern. The distribution of water erosion shows the impact of landforms: slight water erosion mainly in mountainous and hilly areas, and half of violent water erosion on the loess landforms. Farmland, forestland and grassland are the major land use types of slight hydraulic erosion distribution, while the serious hydraulic erosion and slight wind erosion mainly occur on grassland. Thus, the conservation of the grassland is the key to either hydraulic and wind erosion control. The huangmian soil (a major type of cultivated soil developed from loess mother material) is the one facing the most serious threat from soil erosion in chinas soil resources. Further discussion on the soil erosion distribution still needs more research on the method and relevant data analysis.

关键词： soil erosion spatial distribution remote {1. survey china

Metallic Mineral Resources Assessment and Analysis System Design

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2000年第3期19卷 114-117页

作者： Hu Guangdao Chen Jianguo Chen Shouyu Institute of Mathematical geology and {1. sensing, {3. University of Geosciences, Wuhan 43.074, {3.

This paper presents the aim and the design structure of the metallic mineral resources assessment and analysis system. This system adopts an integrated technique of data warehouse composed of affairs processing layer and analysis application layer. The affairs processing layer includes multiform databases (such as geological database, geophysical database, geochemical database), while the analysis application layer includes data warehouse, online analysis processing and data mining. This paper also presents in detail the data warehouse of the present system and the appropriate spatial analysis methods and models. Finally, this paper presents the prospect of the system.

关键词： mineral resources assessment data warehouse spatial analysis.

Gradient analysis of landscape spatial and temporal pattern changes in Beijing metropolitan area

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第S1期53卷 91-98页

作者： YANG YeTao1.ZHOU QiMing2,GONG JianYa3.& WANG YingYing4 1.Institute of Geophysics and Geomatics,{1. University of Geosciences,Wuhan 43.074,{1. 2 Department of Geography,Hong Kong Baptist University,Hong Kong 3.State Key Laboratory of Information Engineering in Surveying,Mapping and remote {3.,Wuhan University,Wuhan 43.074,{1. 4 Hubei Provincial Bureau of Meteorology,Wuhan 43.074,{1. Institute of Geophysics and Geomatics China University of Geosciences Wuhan China Department of Geography Hong Kong Baptist University Hong Kong China State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan China Hubei Provincial Bureau of Meteorology Wuhan China

The gradient based landscape metrics analysis is now widely used to study the landscape pattern changes in respond to the *** order to discover the trend of spatio-temporal changes in Beijing metropolitan area during the past 1. years,several landscape metrics are computed using a moving window along a 96 km long transect across Beijing metropolitan area from west to ***,the spatial extent of sub-landscape,which is determined by the moving window’s size,is profoundly *** results show that the metrics varies smoothly and regularly along the selected transect when the window size is greater than 6 km×6 km,and irregularly fluctuated for the smaller window size,that the spatial and temporal landscape characteristics of Beijing city match the hypothetical framework of spatio-temporal urban sprawl in the form of alternating processes of diffusion and coalescence well,and that some new trends of the urban sprawl style in Beijing metropolitan area,such as leap-frog manner,are also detected by the gradient landscape analysis.

关键词： gradient analysis landscape metrics spatio-temporal urban expansion multi-extent