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

science china Earth sciences 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 sensing 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 sensing 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 20742, USA 1. state key laboratory of remote sensing 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 beijing, 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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Biomass estimation and uncertainty analysis based on CBErS-02 CCD camera data and field measurement

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science china(Technological sciences) 2005年第S2期48卷 116-128页

作者： CHEN Liangfu1,2, GAO Yanhua1,3, CHENG Yu1,3, WEI Zheng1,3, XIAO Qing1,4, LIU Qinhuo1, YU Tao1, LIU Qijing5, GU Xingfa1 & TIAN Guoliang1 1. state key laboratory of remote sensing science, institute of remote sensing applications, chinese academy of sciences, beijing 100101, china 2. Geography and Environment College, Jiangxi Normal University, Nanchang 330027, china 3. Graduate University of chinese academy of sciences, beijing 100039, china 4. beijing research institute of Uranium Geology, beijing 100875, china 5. institute of Geographic sciences and Natural resources research, chinese academy of sciences, beijing 100101, china 1. state key laboratory of remote sensing science Institute of Remote Sensing Applications Chinese Academy of Sciences 100101 Beijing China 2. Geography and Environment College Jiangxi Normal University 330027 Nanchang China 3. Graduate University of chinese academy of sciences 100039 Beijing China 4. beijing research institute of Uranium Geology 100875 Beijing China 5. institute of Geographic sciences and Natural resources research Chinese Academy of Sciences 100101 Beijing China

The study site is located in Qianyanzhou experimental station and the surrounding area. Based on CBErS-02 satellite data and field measurement, we not only discussed the relationship between NDVI and biomass of two species of coniferous plantations, namely, pinus massoniana Lamb and pinus elliottii Engelm, but also introduced the biomass models based on NDVI. The comparison between measured biomass in Qianyanzhou and biomass derived from CBErS-02 CCD data showed that it is feasible to estimate biomass based on NDVI. But its limitations cannot be ignored. This kind of model depends on the dominant vegetation species. There are some effect factors in estimating biomass based on NDVI. This paper analyzes these factors based on fine-resolution CBErS-02 CCD data and some conclusions are drawn: In Qianyanzhou, the area with good vegetation coverage, the nonlinearity of NDVI has little influence on scaling-up of NDVI. As a result of surface heterogeneity, scaling-up can cause NDVI within each pixel to change. Because scaling-up can cause pixel attribute to change, the applicability of biomass model is one of the sources of error in estimating biomass.

关键词： NDVI biomass scaling effect scaling-up.

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Change of surface cover greenness in china between 2000 and 2010

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chinese science Bulletin 2012年第22期57卷 2835-2845页

作者： LIU Shuang1,4& GONG peng1,2,3.state key laboratory of remote sensing science, Jointly Sponsored by institute of remote sensing applications of chinese academy of sciences,and beijing Normal University, beijing 100101, china 2institute for Global Change Studies & Center for Earth System science, Tsinghua University, beijing 100084, china 3Department of Environmental science, policy and Management, University of California, Berkeley, CA94720, USA 4Graduate University of chinese academy of sciences, beijing 100049, china state key laboratory of remote sensing science Jointly Sponsored by Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing China Graduate University of chinese academy of sciences Beijing China institute for Global Change Studies & Center for Earth System science Tsinghua University Beijing China Department of Environmental science Policy and Management University of California Berkeley USA

Surface greenness reflects the situation of vegetation *** index calculated from the red and Near Infrared bands of remote sensing images,whose values indicate the level of photosynthetic activity,is monotonically related to surface greenness when vegetation canopy does not fully cover the background *** for desert regions,vegetation index is positively correlated with vegetation ***,vegetation index can be used to study the change in greenness of desert *** study collected MODIS Normalized Difference Vegetation Index (NDVI) data from 2000 to 2010 and analyzed their change over china in this *** results showed that an increasing trend of NDVI occurred over 66.84% (OLS fitting) or 64.27% (LAD fitting) of china,indicating that china's greenness is increasing ***,desertification of china *** showing large increase in greenness are found in Shaanxi,Shanxi,Ningxia,Henan,Shandong,Qinghai,and Gansu while regions with large decrease in greenness are found in Northeast Inner Mongolia,South Tibet,Jiangsu,and *** of Qinghai,Gansu,Xinjiang and South Tibet could probably be driven by climate *** of greenness in Northeast Inner Mongolia was related to agricultural *** of greenness in Jiangsu and Shanghai was related to rapid *** factors did not exhibit obvious correspondence to the large increase in greenness in Shaanxi,Shanxi,Ningxia and Gansu,indicating that the changes might have been caused by human *** reduction of desert areas in china could probably have been caused by human management and protection at the national scale.

关键词：中国地表覆盖归一化植被指数植被覆盖度沙漠地区 NDVI 西藏南部气候因素

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Monitoring Glacier and Supra-glacier Lakes from Space in Mt. Qomolangma region of the Himalayas on the Tibetan plateau in china

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Journal of Mountain science 2009年第3期6卷 211-220页

作者： YE Qinghua ZHONG Zhenwei KANG Shichang Alfred Stein WEI Qiufang LIU Jingshi key laboratory of Tibetan Environment Changes and Land Surface processes Institute of Tibetan Plateau Research Chinese Academy of Sciences (CAS) Beijing 100085 China 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 International institutefor Geo-Information science and Earth Observation (ITC) PO Box 67500 AA Enschede The Netherlands

Because of the large number and remoteness, satellite data, including microwave data and optical imagery, have commonly been used in alpine glaciers surveys. Using remote sensing and Geographical Information System （GIS） techniques, the paper presents the results of a multitemporal satellite glacier extent mapping and glacier changes by glacier sizes in the Mt. Qomolangma region at the northern slopes of the middle Himalayas over the Tibetan plateau. Glaciers in this region have both retreated and advanced in the past 35 years, with retreat dominating. The glacier retreat area was 3.23 km2 （or o.75 km^2 yr^-1 during 1974 and 1976, 8.68 km^2 （or 0.36 km^2 yr^-1 during 1976 and 1992, 1.44 km^2 （or 0.12 km^2 yr^-1） during 1992-2ooo. 1.14 km^2 （or 0.22 km^2 yr^-1 during 2000-2003, and 0.52 km^2 （or 0.07 km^2 yr^-1 during 2003-2008, respectively. While supra-glacier lakes on the debris-terminus of the rongbuk Glacier were enlarged dramatically at the same time, from 0.05 km^2 in 1974 increased to 0.71 km^2 in 2008, which was more than 13 times larger in the last 35 years. In addition, glacier changes also showed spatial differences, for example, glacier retreat rate was the fastest at glacier termini between 5400 and 5700 m a.s.l than at other elevations. The result also shows that glaciers in the middle Himalayas retreat almost at a same pace with those in the western Himalayas.

关键词： Glacier lake remote sensing Mr. Qomolangma region Himalayas Tibetan plateau

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Automatic generalization of metro maps based on dynamic segmentation

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science china(Technological sciences) 2010年第S1期53卷 158-165页

作者： DONG WeiHua 1,TIAN Yuan 2 & ZHANG Yi 2 1 institute of Geography and remote sensing,beijing Normal University,beijing 100875,china 2 institute of remote sensing and Geographic Information System,peking University,beijing 100871,china 1. institute of Geography and remote sensing Beijing Normal University Beijing 100875 China 2. institute of remote sensing and Geographic Information System Peking University Beijing 100871 China

A metro map is usually optimized for the readability of connections and transportation networks *** order to assure good readability and meet aesthetic considerations,a set of principles for good metro map layout are *** to these principles,a new methodology based on dynamic segmentation is presented to produce the metro maps ***,routes are constructed according to the line attribute similarity and geometry *** a set of cartographic generalization methods about the shape,angle,length,and topology are presented for these *** method is validated by beijing metro plan *** the experiment results,it can be concluded that this new method is more effective than the static segmentation method to produce metro maps with better readability for route plans.

关键词： metro maps generalization dynamic segmentation visualization

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The quantification of remote sensing

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science china(Technological sciences) 2005年第S2期48卷 1-11页

作者： GU Xingfa1,2,3,TIAN Guoliang1,2, LI Xiaowen1,2 & GUO Jianning4 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. The Center for National Spaceborne Demonstration, beijing 100101, china 3. Institut National de la recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 4. china Center for resource Satellite Data and Application, beijing 100830, china chinese Acad Sci Inst Remote Sensing Applicat State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China beijing Normal Univ State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China Ctr Natl Spaceborne Demonstrat Beijing 100101 Peoples R China Inst Natl rech Agron F-84914 Avignon France china Ctr resource Satellite Data & Applicat Beijing 100830 Peoples R China

The paper firstly defined the remote sensing information quantification, analyzed the necessity of developing remote sensing quantification, figured out the application guidelines requirement, and pointed out the importance of quantification research. Then taking the remote sensing application research of CBErS-02 data quantification as the example, the paper described the whole quantification system of “remotely sensed digital signal-radiation information-field parameter inversion”. Finally the paper gave the prospect for the development trend of the quantitative remote sensing.

关键词： remote sensing information quantification CBErS-02 radiometric calibration surface parame- ter reversion.

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Absolute radiometric calibration of CBErS-02 IrMSS thermal band

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science china(Technological sciences) 2005年第S2期48卷 72-90页

作者： ZHANG Yong1,2,3, GU Xingfa1,3,4, YU Tao1,3, ZHANG Yuxiang5, CHEN Liangfu1,3, LI Xiaoying1,2,3, LI Xiaowen1,3 & HE Liming6 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 100039, china 3. The Center for National Spaceborne Demonstration, beijing 100101, china 4. Institut National de la recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 5. National Satellite Meteorological Center, beijing 100081, china 6. state Environmental protection Administration, beijing 100029, china chinese Acad Sci Inst Remote Sensing Applicat State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China beijing Normal Univ State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China chinese Acad Sci Grad Univ Beijing 100039 Peoples R China Ctr Natl Spaceborne Demonstrat Beijing 100101 Peoples R China INrA F-84914 Avignon France Natl Satellite Meteorol Ctr Beijing 100081 Peoples R China state Environm protect Adm Beijing 100029 Peoples R China

Based on the laboratory calibration before launch of CBErS-02 IrMSS thermal infrared channel, the onboard blackbody calibration, the radiometric cross- calibration against TErrA MODIS corresponding channel and the in-flight field calibration at Lake Qinghai: water surface radiometric calibration test site of china on Aug. 17, 2004 are carried out in this research. When making onboard blackbody calibration of CBErS-02 IrMSS, it is necessary to understand inside structures and light path in IrMSS camera and receive and process calibration blackbody signals at normal and high temperatures. Onboard blackbody calibration results of each detector are very important to relative radiometric calibration of images processing and absolute radiometric calibration of each detector. In-flight field calibration mainly contains field experiments, obtaining synchronous images, spectrum marching and MODTrAN radiative transmi- ssion computation. radiometric cross-calibration of CBErS-02 IrMSS thermal band against TErrA MODIS selected 6 times synchronous images of two sensors passing through Lake Qinghai and Lake Taihu from August to December, 2004 to compute the cross calibration data. Combining the in-flight field calibration and radiometric cross calibration data, the absolute radiometric calibration coefficients are calculated by the linear regression method. This new calibration model can obviously control the radiometric calibration uncertainties aroused by the single point method used in the in-flight calibration of CBErS-02 IrMSS, this kind of sensors cannot receive the cosmic background radiation. In this research, the radiometric calibration coefficients obtained through the linear regression model are 8.53 (gain, unit: DN/W m?2sr?1μm?1) and 44.92 (offset, unit: DN).

关键词： CBErS-02 IrMSS thermal band in-flight field calibration onboard blackbody calibration cross calibration.

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Fuzzy entropy image segmentation based on particle swarm optimization

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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 sensing and Information Engineering, Wuhan University, Wuhan 430079, china b state key laboratory of Information Engineering in Surveying, Mapping and remote sensing, Wuhan University, Wuhan 430079, china School of remote sensing 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

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radiometric cross-calibration of the CBErS-02 CCD camera with the TErrA MODIS

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science china(Technological sciences) 2005年第S2期48卷 44-60页

作者： LI Xiaoying1,2,3, GU Xingfa1,3,4, MIN Xiangjun5, YU Tao1,3, FU Qiaoyan5, ZHANG Yong1,2,3 & LI Xiaowen1,3 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 100039, china 3. The Center for National Spaceborne Demonstration, beijing 100101, china 4. Institut National de la recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 5. china Center for resource Satellite Data and Application, beijing 100830, 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 100101 Beijing China 2. Graduate University of chinese academy of sciences 100039 Beijing China 3. The Center for National Spaceborne Demonstration 100101 Beijing China 4. Institut National de la recherche Agronomique Climat Sol Environnement 84914 Avignon France 5. china Center for resource Satellite Data and Application 100830 Beijing China

For the application of the CCD camera, the most important payload on CBErS-02, the key is to provide long-term stable radiometric calibration coefficients. Although the vicarious calibration had been proved successful, it had its limitations such as test site requirement and unsuitable for historical data. Cross-calibration is one of the alternative methods, but it needs synchro surface spectrum to achieve spectral band matching factors. Our effort is to probe the influences on these factors. Simulations with a lot of surface spectrum showed that the factors changed with the viewing geometry, atmospheric condition and surface targets. However, simulating with the same viewing geometry and atmospheric condition, the spectral band matching factors of the same or similar surface targets’ spectrum acquired from different dates and different places would like to be consistent to each other within 1%―5%. Thus, the synchro measurement data can be substituted by the same or similar target from other source. Based on this method, using the MODIS as the reference, the cross-calibration was performed for CCD camera. The research demonstrated that the traditional method with single calibration site was inappropriate for CCD camera, since the offsets for its four spectral bands were not zeros. With four calibration sites, these offsets were obtained. And the camera was detected to degrade with dates based on four times of cross-calibrations.

关键词： CBErS-02 CCD camera cross-calibration the spectral band matching factors.

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Image City sharing platform and its typical applications

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science china(Information sciences) 2011年第8期54卷 1738-1746页

作者： SHAO ZhenFeng & Li Deren state key laboratory for Information Engineering in Surveying,Mapping and remote sensing,Wuhan University,Wuhan 430079,china 1. state key laboratory for Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China

In this paper,the trend of urban spatial information sharing service from the electronic map to image is analyzed and its sharing framework based on service-oriented architecture is ***,the service implementation,feedback data service procedure and its processing service model are explored. Based on the software with independent intellectual property rights,image city of Taizhou is developed as an example to realize various image data and processing servicesLastly,the bright future prospects of image city are described.

关键词： Image City service-oriented architecture image data service function service model service

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