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Retrieving crop leaf area index by assimilation of MODIS data into a crop growth model

science china Earth {2. 2010年第5期53卷 721-730页

作者： WANG DongWei1,2.3, WANG JinDi1,2.& LIANG ShunLin4 1 State key Laboratory of remote {2. science, Jointly Sponsored by beijing Normal University and institute of remote sensing applications, CAS, beijing 100875, china 2.School of Geography, beijing key Laboratory of Environmental remote {2. and Digital City, beijing Normal University, beijing 100875, china 3 Haihe River Water Conservancy Commission, Tianjin 300170, china 4 Department of Geography, University of Maryland, College Park, MD 2.742. USA 1. State key Laboratory of remote {2. science Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing Applications CAS Beijing 100875 China2. School of Geography Beijing Key Laboratory of Environmental Remote Sensing and Digital City Beijing Normal University Beijing 100875 China3. Haihe River Water Conservancy Commission Tianjin 300170 China4. Department of Geography University of Maryland College Park MD 20742 USA

Leaf area index (LAI) is an important parameter in monitoring crop growth. One of the methods for retrieving LAI from remotely sensed observations is through inversion of canopy reflectance models. Many model inversion methods fail to account for variable LAI values at different crop growth stages. In this research, we use the crop growth model to describe the LAI changes with crop growth, and consider a priori LAI values at different crop growth stages as constraint information. The key approach of this research is to assimilate multiple canopy reflectance values observed at different growth stages and a priori LAI values into a coupled crop growth and radiative transfer model sequentially using a variational data assimilation algorithm. Adjoint method is used to minimize the cost function. Any other information source can be easily incorporated into the inversion cost function. The validation results show that the time series of MODIS canopy reflectance can greatly reduce the uncertainty of the inverted LAI values. Compared with MODIS LAI product at Changping and Shunyi Counties of {2., this method has significantly improved the estimated LAI temporal profile.

关键词： inversion leaf area index crop growth model time series MODIS

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Land cover classification of remotely sensed image with hierarchical iterative method

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Progress in Natural science:Materials International 2005年第5期15卷 442-447页

作者： LI Peijun* and HUANG Yingduan(institute of remote {2. and GIS, Peking University, beijing 100871, china) institute of remote {2. and GIS Peking University Beijing 100871 China

Based on the analysis of the single-stage classification results obtained by the multitemporal SPOT 5 and Landsat 7 ETM+ multispectral images separately and the derived variogram texture, the best data combinations for each land cover class are selected, and the hierarchical iterative classification is then applied for land cover mapping. The proposed classification method combines the multitemporal images of different resolutions with the image texture, which can greatly improve the classification accuracy. The method and strategies proposed in the study can be easily transferred to other similar applications.

关键词： multitemporal iterative classification texture land cover image classification.

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In flight MTF monitoring and compensation for CCD camera on CBERS-02

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science china(Technological {2.) 2005年第S2期48卷 29-43页

作者： GU Xingfa1,2.3, LI Xiaoying1,2.4, MIN Xiangjun5, YU Tao1,2. SUN Jijuan5, ZENG Yong1,2.4, XU Hua1,2.& GUO Ding2.6 1. State key Laboratory of remote {2. science, Jointly Sponsored by the institute of remote sensing applications of chinese academy of sciences and beijing Normal University, beijing 100101, china 2. The Center for national Spaceborne Demonstration, beijing 100101, china 3. Institut national de la Recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 4. Graduate University of chinese academy of sciences, beijing 100039, china 5. china Center for Resource Satellite Data and Application, beijing 100830, china 6. University of Electronic science and Technology of china, Chengdu 610054, china State key Laboratory of remote {2. science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University 100101 Beijing China The Center for national Spaceborne Demonstration 100101 Beijing China Institut national de la Recherche Agronomique Climat Sol Environnement 84914 Avignon France Graduate University of chinese academy of sciences 100039 Beijing China china Center for Resource Satellite Data and Application 100830 Beijing China University of Electronic science and Technology of china 610054 Chengdu China

In this article, the approach of simulating ideal tarp scene was proposed to determine the MTF for CCD camera on CBERS-02. The MTF acquired from this technique was compared to those from some common methods. MTFs achieved from different approaches were employed to compensate the CCD images based on three restoration algorithms: the iterative method, the Wiener filter and the modified inverse filter (MIF). The two-dimensional MTF was established with the value at frequency 0.5 for 45° directional MTF as the value at its four corners. This article addressed the variations of the restored CCD images with different techniques of constructing two-dimensional MTF, restoring algorithms and determining the in-flight MTFs. Results showed images restored with the MTF determined from the technique of simulating ideal tarp scene represent the real scene best. And the restoration technique based on the MIF would produce better restored images than the other two techniques. This research also demonstrated that the two-dimensional MTF used for restoration should be interpolated under the control of the MTF for 45° axis, rather than by multiplying the cross-orbit MTF with along-orbit MTF.

关键词： CBERS-02 CCD MTF the technique of simulating ideal tarp scene.

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

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science china(Information {2.) 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 {2. science,Jointly Sponsored by beijing Normal University and the institute 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 {2. 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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Framework and development of digital china

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science china(Technological {2.) 2008年第S1期51卷 1-5页

作者： WU Lun & TONG QingXi institute of remote {2. and Geographical Information Systems,Peking University,beijing 100871,china 1. institute of remote {2. and Geographical Information Systems Peking University Beijing 100871 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 {2. 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

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Plotting the Sequential Rock remote sensing Information by Optimization Dichotomy Method

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Journal of Earth science 1999年第3期18卷 271-273页

作者： Liu Qingsheng Lin Qizhong Wang Zhigang Yan Shouxun(institute of remote {2. Application, chinese academy of sciences, beijing 100101) institute of remote {2. Application Chinese Academy of Sciences Beijing 100101

The sequential rock remote sensing information is a group of rocks that are correlative in space or in space and time. For the sake of plottiug them, someone had brought forward the optimization *** metkod. We have ased this method to plot the sequential rock remote sensing information at tbe remote sensing hyperspetral test field of Daqing mountain, Inner Mongolia Autonomous Region, china, and found some disadvantages of this method. Therefore, we put forward the optimization dichotomy to plot them, and get better results. Finally we make a conclusion.

关键词： sequential rock remote sensing information optimization segmentation method,optimization dichotomy method

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Water target based cross-calibration of CBERS-02.CCD camera with MODIS data

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science china(Technological {2.) 2005年第S2期48卷 61-71页

作者： TANG Junwu1,2. GU Xingfa2. NIU Shengli1, MA Chaofei1 & MIN Xiangjun3 1. national Satellite Ocean Application Service (NSOAS), beijing 100081,{2. 2. State key Laboratory of remote sensing science, beijing 100010,{2. 3.{2. Center for Resource Satellite Data and applications (CRESDA), beijing 100083,{2. 1. national Satellite Ocean Application Service (NSOAS) 100081 Beijing China 2. State key Laboratory of remote {2. science 100010 Beijing China 3. china Center for Resource Satellite Data and applications (CRESDA) 100083 Beijing China

In order to make quantitative watercolor sensing with china-Brazil Earth Resources Satellite (CBERS-02. CCD camera, the MODIS data with higher accuracy is used to cross-calibrate the CCD camera over water targets. In homogeneous clear water area, two pairs of images obtained over the same area on the same day by the two sensors are selected. The top-of-atmosphere (TOA) radiances of the multispectral bands of CCD are calculated with the water and aerosol parameters from MODIS based on a water-atmosphere radiative transfer algorithm. The stripes in CCD image that caused by unequal response of the CCD array detectors are firstly removed before making the cross-calibration. The same part of CCD detectors is selected for the calibrations in the two images to eliminate the residual error of destriping and uniformity correction for the focus plane irradiance. It is shown that the calibration results from two different images are consistent. The error of this method is about 5%.

关键词： CBERS-02 CCD MODIS radiometric calibration cross-calibration. DOI: 10.1360/05ze1006

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Quantitative estimation of the shrub canopy LAI from atmosphere-corrected HJ-1 CCD data in Mu Us Sandland

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science china Earth {2. 2010年第S1期53卷 26-33页

作者： CHEN Wei1,2,CAO ChunXiang1,HE QiSheng1,2,GUO HuaDong3,ZHANG Hao1,2,LI RenQiang4,ZHENG Sheng1,2,XU Min1,2,GAO MengXu1,2,ZHAO Jian1,2,LI Sha1,NI XiLiang1,2,JIA HuiCong1,JI Wei1,TIAN Rong1,2,LIU Cheng1,2,ZHAO YuXing5 & LI JingLu6 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 2 Graduate University of chinese academy of sciences,beijing 100049,china 3 Center for Earth Observation and Digital Earth,chinese academy of sciences,beijing 100190,china 4 china key Laboratory of Ecological Network Observation and Modeling,institute of Geographical sciences and Natural Resources Research,chinese academy of sciences,beijing 100101,china 5 Ordos Forestry Sand Control science institute,Dongsheng 017000,china 6 Inner Mongolia Biomass Thermoelectricity Limited Company,Wushen 017300,china 1. State key Laboratory of remote {2. science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China 2. Graduate University of chinese academy of sciences Beijing 100049 China 3. Center for Earth Observation and Digital Earth Chinese Academy of Sciences Beijing 100190 China 4. china key Laboratory of Ecological Network Observation and Modeling Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China 5. Ordos Forestry Sand Control science institute Dongsheng 017000 China 6. Inner Mongolia Biomass Thermoelectricity Limited Company Wushen 017300 China

The leaf area index(LAI) is an important ecological parameter that characterizes the interface between vegetation canopy and the *** addition,it is used by most process-oriented ecosystem *** paper investigates the potential of HJ-1 CCD data combined with linear spectral unmixing and an inverted geometric-optical model for the retrieval of the shrub LAI in Wushen Banner of Inner Mongolia in the Mu Us ***(Moderate Resolution Atmospheric Radiance and Transmittance Model) was used for atmospheric *** was extracted using the threshold of the normalized difference vegetation index,with which water bodies and farmland were separated,in combination with a vegetation map of the People's Republic of china(1:1000000).Using the geometric-optical model,we derive the per-pixel reflectance as a simple linear combination of two components,namely sunlit background and *** fraction of sunlit background is related to the shrub *** the support of HJ-1 CCD data,we employ linear spectral unmixing to obtain the fraction of sunlit background in an atmospherically corrected HJ *** addition,we use the measured shrub canopy structural parameters for shrub communities to invert the geometric-optical model and retrieve the pixel-based shrub *** total,18 sample plots collected in Wushen Banner of Inner Mongolia are used for *** results of the shrub LAI show good agreement with R2.of 0.817 and a root-mean-squared error of 0.173.

关键词： shrub leaf area index inversion HJ-1 data geometric-optical model MODTRAN Mu Us Sandland

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Co-seismic ground deformation and source parameters of Mani M7.9 earthquake inferred from spaceborne D-InSAR observation data

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science china Earth {2. 2004年第6期47卷 481-488页

作者： SHAN Xinjian1,MA Jin1,WANG Changlin2.LIU Jiahang1,SONG Xiaoyu1 & ZHANG Guifang1 1.institute of Geology and Laboratory of Tectonophysics,china Seismological Bureau,{2. 10002.,china 2.institute of remote sensing Application,chinese academy of sciences,{2. 100101,china 1. institute of Geology and Laboratory of Tectonophysics China Seismological Bureau 100029 Beijing China 2. institute of remote {2. Application Chinese Academy of Sciences 100101 Beijing China

We obtain the co-seismic ground deformation field of the Mani M7.9 earthquake on November 8, 1997 through three-pass differential interferometric processing. Then we get the geometric and kinematics parameters of this event by the elastic half-space model and forward modeling with the InSAR data. The following results have been obtained: (i) The deformation fields on both sides of the seismogenic fault are affected by the co-seismic deformation field even in 110 km away from the fault. The loss of phase coherence belt caused by the zone of ground rupture crosses the image from east to west with a length of an area 110 km. (ii) The maximum horizontal displacement caused by the earthquake reaches 7.96 m. (iii) The earthquake fault can be divided into four parts, and the deformation field of the middle two parts is bigger than that of the other two, with lengths of 2. km and 37 km, respectively. And their average sliding values on the rupture surface are 6500 mm and 6000 mm, respectively, and their depths both are 35 km. The segment of 2. km length is the major rupture surface of this earthquake. The west part and the east part of the fault have lengths of 2. km and 2. km, respectively. The sliding value of the west one is 4000 mm and that of the east one is 5800 mm. They extend to depths of 2. km and 18 km, respectively.

关键词： D-InSAR, surface deformation field in sight direction, Mani earthquake, characteristics of earthquake fault.

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Investigation of fine and complex vortex circulation structures

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science china Earth {2. 2010年第10期53卷 1552-1558页

作者： LUO ZheXian1,MA GeLan1 & PING Fan2.1 remote sensing College,Nanjing University of Information {2. and Technology,Nanjing 2.0044,china 2.Laboratory of Cloud-Precipitation Physics and Severe Storms(LACS),institute of Atmospheric Physics,chinese academy of sciences,beijing 10002.,china 1. remote sensing College Nanjing University of Information Science and Technology Nanjing 210044 China2. Laboratory of Cloud-Precipitation Physics and Severe Storms (LACS) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The formation and evolution of fine and complicated vortex circulation structures were investigated using a two-dimensional quasi-geostrophic barotropic model *** find that the highly localized asymmetric and complex configuration of energy transfer flux between large-and small-scale components is caused by the nonlinear interaction between a large-scale vortex with an initial axi-symmetric flow and four beta meso-scale *** complex structure is characterized by a fine pattern,which contains seven closed systems with spatial scales of less than 100 km,embedded in a positive flux wave train and a negative wave train,*** average wind speed decreased with time in the positive flux region,but was nearly unchanged in the negative flux *** pattern reveals the evolutionary asymmetry and localization of wind speed of the major *** track of the major vortex center has a trend toward the center of the negative flux center,indicating that there is a certain relation between the complex structure of the energy transfer flux and the motion of the major vortex *** results imply that the formation and evolution of the fine and complex structure should be attributed to the nonlinear interaction between the vortices at different spatial scales.

关键词： vortex complex structure non-linear interaction energy cascade

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