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A new trust region algorithm for image restoration

science china Mathematics 2005年第2期48卷 169-184页

作者： WEN Zaiwen & WANG Yanfei State key laboratory of Scientific Engineering Computing, institute of Computational Mathematics and Scientific/Engineering Computing, {3. of Mathematics and System sciences, chinese {3. of sciences, beijing 100080, china National key laboratory on {12. {{13. science, institute of {12. {{13. Applications, chinese {3. of sciences, beijing 100101, china 1. State key laboratory of Scientific Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and System Sciences Chinese Academy of Sciences 100080 Beijing China 2. National key laboratory on {2. {3. science Institute of Remote Sensing Applications Chinese Academy of Sciences 100101 Beijing China

The image restoration problems play an important role in remote sensing and astronomical image analysis. One common method for the recovery of a true image from corrupted or blurred image is the least squares error (LSE) method. But the LSE method is unstable in practical applications. A popular way to overcome instability is the Tikhonov regularization. However, difficulties will encounter when adjusting the so-called regularization parameter a. Moreover, how to truncate the iteration at appropriate steps is also challenging. In this paper we use the trust region method to deal with the image restoration problem, meanwhile, the trust region subproblem is solved by the truncated Lanczos method and the preconditioned truncated Lanczos method. We also develop a fast algorithm for evaluating the Kronecker matrix-vector product when the matrix is banded. The trust region method is very stable and robust, and it has the nice property of updating the trust region automatically. This releases us from tedious finding the regularization parameters and truncation levels. Some numerical tests on remotely sensed images are given to show that the trust region method is promising.

关键词： trust region algorithm, image restoration, Lanczos method, Kronecker matrix-vector product, preconditioning.

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Latent ancestral graph of structure vector autoregressive models

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Journal of Systems Engineering and Electronics 2010年第2期21卷 233-238页

作者： Wei Gao1,2.nd Zheng Tian2.3.1.School of Statistics,Xi’an University of Finance&Economics,Xi’an 710061,p.r.china 2.Department of Applied Mathematics,Northwestern polytechnical University,Xi’an 710072.p.r.china 3.State key {3. of remote sensing science,institute of remote sensing Applications,{12. academy of sciences,{{13.,p.r.china School of Statistics Xi'an University of Finance & EconomicsXi'an 710061P.R.China Department of Applied Mathematics Northwestern Polytechnical UniversityXi'an 710072P.R.China Department of Applied Mathematics Northwestern Polytechnical UniversityXi'an 710072P.R.China State key laboratory of {2. {3. science Institute of Remote Sensing ApplicationsChinese Academy of SciencesBeijing 100101P.R.China

A class of latent ancestral graph for modelling the dependence structure of structural vector autoregressive （VAr） model affected by latent variables is proposed. The graphs are mixed graphs with possibly two kind of edges, namely directed and bidirected edges. The vertex set denotes random variables at dif- ferent times. In Gaussian case, the latent ancestral graph leads to a simple parameterization model. A modified iterative conditional fitting algorithm is presented to obtain maximum likelihood esti- mation of the parameters. Furthermore, a log-likelihood criterion is used to select the most appropriate models. Simulations are performed using illustrative examples and results are provided to demonstrate the validity of the methods.

关键词： multivariate time series latent ancestral graph itera- tive conditional fitting.

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Effective solutions to a global 3. visual system in networking environments

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science china Earth sciences 2005年第11期48卷 2032-2039页

作者： ZHANG Liqiang1,2, ZHANG Yan3. YANG Chongjun2, LIU Suhong1, rEN Yingchao2, rUI Xiaoping2 & LIU Donglin2 1. State key laboratory of remote {3. sciences, School of Geography and remote {3., beijing Normal University, beijing 100875, china 2. State key laboratory of remote {3. sciences, institute of remote {3. Applications, chinese academy of sciences, beijing 101001, china 3. institute of Geographical sciences and Natural resources research, chinese academy of sciences, beijing 101001, china 1. State key laboratory of {2. {3. sciences School of Geography and Remote Sensing Beijing Normal University 100875 Beijing China 2. chinese academy of {2.s State Key Laboratory of Remote Sensing SciencesInstitute of Remote Sensing Applications 101001 Beijing China 3. institute of Geographical {2.s and Natural resources research Chinese Academy of Sciences 101001 Beijing China

The development of Web-based global 3. visual system has made progresses. However, there exist few mature and effective ways for managing, transmitting and visualizing massive spatial data. Based on the related work, the paper illustrates the ellipsoidal quadtree technique for rapid access multi-scale and multiple level geographical data, integrates the streaming with level-of-detail rendering method for transmitting the data on the network, and im-plements large-scale terrain surface simplification using M-band wavelet transforms and mul-tiresolution triangulations. We fulfil a web-based global terrain visual system using COM com-ponents on the basis of the above techniques. The system has a good prospect in the military simulation and city plans.

关键词： massive spatial data, streaming transmission, system architecture, M-band wavelet

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Monitoring of rice crop using ENVISAT ASAr data

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science china Earth sciences 2006年第7期49卷 755-763页

作者： DONG Yanfang1, 2. SUN Guoqing1,3.& pANG Yong4 1. State key {2. of remote {3. science, institute of remote {3. Applications, chinese academy of sciences, {12., {12. 2. Graduate University of chinese academy of sciences, beijing 10003., {12. 3. Department of Geography, University of Maryland, College park, MD 2.742. USA 4. Forest remote {3. Lab, research institute of Forest resource and Information Technology, chinese academy of For-estry, beijing 100091, {12. 1. State key laboratory of {2. {3. science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China 2. Graduate University of chinese academy of {2.s Beijing 100039 China 3. Department of Geography University of Maryland College Park MD 20742 USA 4. Forest remote sensing Lab Research Institute of Forest Resource and Information Technology Chinese Academy of Forestry Beijing 100091 China

Because of the cloudy conditions during the rice growth period, rice is one of the agri-cultural crops most suited to monitoring with the SAr instruments. Backscatter response measured by SAr is correlated with rice conditions, including height, density, biomass and structure, which are variable at different growing stages. In this paper, multi-date ENVISAT ASAr Alternating polarization Mode (ApMode) imageries were acquired during the rice crop growing cycle. At the same time, the rice parameters were measured in field. A continuous canopy model was used to compute the back-scattering from rice fields during the growth cycle, and the relationship between rice parameters and radar backscattering coefficients from both ASAr and modeling was analyzed. The effects of polari-zation, incidence angle and polarization on radar backscattering coefficients were analyzed. It was found that simulated radar backscatter has similar trends as ASAr data. This will be meaningful for the further research of rice parameters estimation from ASAr data. Different features show signifi-cantly different signatures in ASAr images and they follow some certain laws, so rice area can be accurately mapped by using multi-temporal SAr images, then rice yield can be estimated.

关键词： rice, ASAr, radar backscattering, model.

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Observing seasonal variations of sea surface wind speed and significant wave height using TOpEX altimetry

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chinese science Bulletin 2000年第14期45卷 1323-1328,1345-1346页

作者： CHEN Ge & LIN Hui1. laboratory of remote {2. Information {3., institute of remote {2. Applications, chinese academy of {3.s, beijing 100101, china 2. Ocean remote {2. institute, Ocean University of Qingdao, Qingdao 2.6003. china 3. CAS/CUHK Joint laboratory for Geo-Information {3. and Department of Geography, the chinese University of Hong Kong, Shatin, New Territories, Hong Kong, chinaCorrespondence should be addressed to Chen Ge laboratory of remote {2. Information {3. Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing China Ocean remote sensing {2. Ocean University of Qingdao Qingdao China CAS/CUHK Joint laboratory for Geo-Information science and Department of Geography The Chinese University of Hong Kong Shatin New Territories Hong Kong China

One year of ocean topography experiment (TOpEX) altimeter data are used to study the seasonal variations of global sea surface wind speed and significant wave height. The major wind and wave zones of the world oceans are precisely identified, their seasonal variability and characteristics are quantitatively analyzed, and the diversity of global wind speed seasonality and the variability of significant wave height in response to sea surface wind speed are also revealed.

关键词： satellite altimeter sea surface wind speed significant wave height seasonal variation.

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Long term monitoring of urban subsidence by permanent Scatterer DInSAr

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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 {2. Satellite Ground Station, chinese academy of sciences, beijing 100086, china State key laboratory of remote {2. IrSA, chinese academy of sciences, beijing 100101, china) [a]The chinese remote {2. Satellite Ground Station Chinese Academy of Sciences Beijing China [b]State key laboratory of {2. {3. IrSA Chinese Academy of Sciences Beijing 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 2. ErS-1/2.scenes from 1992.to 2.00 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.

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Development of environmental monitoring satellite systems in china

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science china Earth sciences 2010年第S1期53卷 1-7页

作者： LI Guoping1 & CAO ChunXiang2.1 School of Earth and Space sciences,peking University,beijing 100871,{2. 2.State {3. laboratory of remote sensing science,Jointly Sponsored by the institute of remote sensing Applications of chinese {{12. of sciences and beijing Normal University,beijing 100101,{2. 1. School of Earth and Space sciences Peking University Beijing 100871 China2. State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China

With the increase in global environmental problems,the necessity and urgency of remote sensing technology being applied to environmental monitoring has been widely recognized around the *** has launched the environment and disaster monitoring and forecasting small satellite constellation HJ-1A/B and the FY{2.atmosphere and environmental satellite,but they still cannot fully satisfy requirements for environmental *** paper summarizes the current status of satellite environmental monitoring in china and the existing problems of inadequate load design and low data utilization efficiency,and discusses the demand for environmental monitoring *** on the development of foreign satellite systems for environmental monitoring,the future development and {{2. tasks of the environmental monitoring satellite system in china is discussed,as are some related initiatives.

关键词： environmental satellite environmental monitoring global climate change specialty load satellite system

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Scale effects of leaf area index inversion based on environmental and disaster monitoring satellite data

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science china Earth sciences 2010年第S1期53卷 92-98页

作者： ZHANG Hao1,LI XiaoWen1,2.CAO ChunXiang1,YANG Hua2.GAO MengXu1,3.ZHENG Sheng1,3.XU Min1,3.XIE DongHui2.JIA HuiCong1,JI Wei1,ZHAO Jian1,3.CHEN Wei1,3.& NI XiLiang1,3.1 State key laboratory of remote {3. science,Jointly Sponsored by institute of remote {3. Applications,chinese academy of sciences and beijing Normal University,{12.,{{13. 2.State key laboratory of remote {3. science,Jointly Sponsored by beijing Normal University and institute of remote {3. Applications of chinese academy of sciences,beijing 100875,{{13. 3.Graduate University of chinese academy of sciences,beijing 100049,{{13. 1. State key laboratory of {2. {3. science Jointly Sponsored by Institute of Remote Sensing Applications Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China2. State Key Laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing Applications of Chinese Academy of Sciences Beijing 100875 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China

The spatial distribution of sub-pixel components has an impact on retrieval accuracy,and should be accounted for when inverting a three-dimensional adiative transfer model to retrieve leaf area index(LAI).To investigate this effect,we constructed three realistic scenarios with the same LAI values and other properties,except that the simulated plants had different *** implemented the radiosity method to subsequently produce synthetic bidirectional reflectance factor(BrF) datasets based upon these simulated *** inversion was conducted using these data,which showed that spatial distribution affects retrieval *** inversion was also conducted for LAI based on charge-coupled device(CCD) data from the Environment and Disaster Monitor Satellite(HJ-1),which depicted both forest and drought-resistant crop land *** showed that heterogeneity in coarse-resolution remote sensing data is the main error source in LAI *** spatial distribution of global fractal dimension index,which can be used to describe the area of sub-pixel components and their spatial distribution modes,shows good consistency with the coarse resolution LAI inversion error.

关键词： HJ-1 leaf area index scale effect spatial distribution

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parallel algorithm for real-time contouring from grid DEM on modern GpUs

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science china(Technological sciences) 2010年第S1期53卷 33-37页

作者： CHEN Zhuo,SHEN Lei,ZHAO YanQing & YANG ChongJun State key laboratory of {2. {3. science,Jointly Sponsored by the institute of {2. {3. Applications of chinese academy of sciences and beijing Normal University,{{12.,{{13. 1. State key laboratory of {2. {3. science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China

A real-time algorithm for constructing contour maps from grid DEM data is *** runs completely within the programmable 3. visualization *** interpolation is paralleled by rasterizer units in the graphics card,and contour line extraction is paralleled by pixel *** each frame of the rendering,we first make an elevation gradient map out of original terrain vertex data,then figure out the final contour lines with image-space processing,and directly blend the results on the original scene to obtain a final scene with contour map using *** implement this method in our global 3.-digitalearth system with Direct3.?9.0c ApI and tested on some consumer level pC *** arbitrary scene with certain LOD level,the process takes less than 10 ms,giving topologically correct,anti-aliased contour lines.

关键词： contour map contour lines paralleled computing 3. terrain GpU digital earth

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Detection of the urban heat island in beijing using HJ-1B satellite imagery

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science china Earth sciences 2010年第S1期53卷 67-73页

作者： YANG Jun1,GONG peng2.ZHOU JinXing3.HUANG HuaBing2.& WANG Lei2.1 key {2. of Silviculture and Conservation,Ministry of Education,beijing Forestry University,beijing 100083.china 2.State key {2. of remote sensing science,jointly sponsored by the {12. of remote sensing Applications,{{13. academy of sciences and beijing Normal University,beijing 100101,china 3.{12. of Desertification Studies,{{13. academy of Forestry,beijing 100091 china 1. key laboratory of Silviculture and Conservation Ministry of Education Beijing Forestry University Beijing 100083 China2. State Key Laboratory of Remote Sensing Science jointly sponsored by the Institute of Remote Sensing Applications Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China3. Institute of Desertification Studies Chinese Academy of Forestry Beijing 100091 China

Satellite images are used extensively in studying the urban heat island(UHI) *** evaluated the suitability of thermal infrared(TIr) data from the HJ-1B satellite for detecting UHI using a case study in *** modified algorithms for retrieving the land surface temperature(LST) from HJ-1B data were *** results were compared with LST images derived from a Landsat TM thermal band and the MODIS LST *** spatial pattern of UHI generated using HJ-1B data matched well with that produced using TM and MODIS *** the two algorithms,the mono-window algorithm performed better but further tests are *** more frequent coverage than TM and higher spatial resolution than MODIS,the HJ-1B TIr data present a unique opportunity to study thermal environments in cities in china and neighboring countries.

关键词： surface temperature NDVI mono-window algorithm single-channel algorithm

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