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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, academy of Mathematics and System sciences, chinese academy of sciences, beijing 100080, china National key laboratory on remote sensing science, Institute of remote sensing Applications, chinese academy 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 remote sensing 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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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 sensing Satellite Ground Station, chinese academy of sciences, beijing 100086, china state key laboratory of remote sensing IRSA, chinese academy of sciences, beijing 100101, china) [a]The chinese remote sensing Satellite Ground Station Chinese Academy of Sciences Beijing China [b]state key laboratory of remote sensing 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 25 ERS-1/2 scenes from 1992 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.

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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,china 2.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 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 FY3 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 key 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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Effective solutions to a global 3D 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 sensing sciences, School of Geography and remote sensing, beijing Normal University, beijing 100875, china 2. state key laboratory of remote sensing sciences, Institute of remote sensing 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 remote sensing sciences School of Geography and Remote Sensing Beijing Normal University 100875 Beijing China 2. chinese academy of sciences State Key Laboratory of Remote Sensing SciencesInstitute of Remote Sensing Applications 101001 Beijing China 3. Institute of Geographical sciences and Natural Resources Research Chinese Academy of Sciences 101001 Beijing China

The development of Web-based global 3D 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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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 remote sensing science,Jointly Sponsored by the Institute of remote sensing Applications of chinese academy of sciences and beijing Normal University,beijing 100101,china 1. 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

A real-time algorithm for constructing contour maps from grid DEM data is *** runs completely within the programmable 3D 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 3D-digitalearth system with Direct3D?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 3D terrain GPU digital earth

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Photosynthetically active radiation retrieval based on HJ-1A/B satellite data

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science china Earth sciences 2010年第S1期53卷 81-91页

作者： LI Li1,XIN XiaoZhou1,SU GaoLi1,2 & LIU QinHuo1 1 state key laboratory of remote sensing science,Institute of remote sensing Applications,chinese academy of sciences,beijing 100101,china 2 Zhejiang Climate Center,Hangzhou 310017,china 1. state key laboratory of remote sensing science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China2. Zhejiang Climate Center Hangzhou 310017 China

Photosynthetically active radiation(PAR) is essential for plant photosynthesis and carbon cycle,and is also important for meteorological and environmental *** advance china's disaster and environmental monitoring capabilities,the HJ-1A/B satellites have been placed in Earth *** of their environmental monitoring objectives is the study of *** simulated direct solar,scattered and environment radiation between 400 and 700 nm under different atmospheric parameters(solar zenith angle,atmospheric water vapor,atmospheric ozone,aerosol optical thickness,surface elevation and surface albedo),and then established a look-up table between these input parameters and *** on the look-up table,we used HJ-1A/B aerosol and surface albedo outputs to derive the corresponding *** of inversed instantaneous and observed PAR values using HJ-1 Heihe experimental data had a root mean square error of 25.2 W m-2,with a relative error of 5.9%.The root mean square error for accumulated daily PAR and observed values was 0.49 MJ m-2,with a relative error of 3.5%.Our approach improved significantly the computational efficiency,compared with using directly radiation transfer *** also studied the sensitivity of various input parameters to photosynthetically active radiation,and found that solar zenith angle and atmospheric aerosols were sensitive PAR *** albedo had some effect on PAR,but water vapor and ozone had minimal impact on PAR.

关键词： Photosynthetically active radiation 6S HJ-1A/B satellites

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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 sensing science,Jointly Sponsored by Institute of remote sensing Applications,chinese academy of sciences and beijing Normal University,beijing 100101,china 2.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,china 3 Graduate University of chinese academy of sciences,beijing 100049,china 1. state key laboratory of remote sensing 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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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 laboratory of Silviculture and Conservation,Ministry of Education,beijing Forestry University,beijing 100083,china 2.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,china 3 Institute of Desertification Studies,chinese 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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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 Gao1,2and 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 laboratory of remote sensing science,Institute of remote sensing Applications,chinese academy of sciences,beijing 100101,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 remote sensing 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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Multiple time scale evaluation of the energy balance during the maize growing season,and a new reason for energy imbalance

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science china Earth sciences 2009年第1期52卷 108-117页

作者： GUO JianXia1,2,BIAN LinGen3 & DAI YongJiu2 1 Meteorological Observation Center of china Meteorological Administration,beijing 100081,china 2.state key laboratory of remote sensing science,School of Geography and remote sensing science,beijing Normal University,beijing 100875,china 3 chinese academy of Meteorological sciences,beijing 100081,china Meteorological Observation Center of china Meteorological Administration Beijing 100081 China state key laboratory of remote sensing science School of Geography and Remote Sensing Science Beijing Normal University Beijing 100875 China

Energy imbalance is a common problem associated with the measurement of surface energy using the eddy covariance *** the evaluation of the energy balance,people usually pay more attention to the statistical result that the effective energy(the sum of sensible and latent heat) is systematically lower than the available energy(the difference of net radiation and ground heat flux).However,little attention has been paid to the existence of the reversed situation when the effective energy is larger than the available energy or their contribution to the overall energy closure *** this paper,based on the analysis of the energy balance on multiple time scales across the maize growth season,we conclude that the non-synchronization of energy components is the main reason for the existence of the reversed *** shifting the phase of the effective energy components half an hour ahead,the rates of energy closure over all time scales are improved and dramatically reduce the number of the half-hourly samples when the energy ratio exceeds 1 or is below *** to the characteristics of the energy distribution and transformation over multiple time scales,latent heat is always the main type of energy cost,and the residual of the energy balance increases with the growth of the maize plant surpassing the sensible heat for seventy *** is suggested that the heat storage and photosynthetic energy play an important role in the energy balance during the growing period of maize.

关键词： maize energy balance multiple time scale energy hysteresis

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