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Comparison of the influence factors on NDVI for CCD camera and WFI imager on CBERS-02

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science China(Technological sciences) 2005年第S2期48卷 100-115页

作者： YU Tao1,3, LI Xiaoying1,2.3, ZHANG Yong1,2.3, ZHAO Feng1,2.3, GU Xingfa1,3,4, ZHU Li1,2.3, WANG Pengxin5 & MIN Xiangjun6 1. state key {2. of {2. sensing science Institute of {2. sensing Application, CAS, Bei- jing 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. College of Information and Electrical Engineering, China Agricultural University, beijing 100083, China 6. China Center for Resource Satellite Data and Application, beijing 100830, China state key {2. of {2. sensing science Institute of Remote Sensing Application CAS Beijing 100101 China Center for National Spaceborne Demonstration Beijing 100101 China Graduate University Chinese Academy of Sciences Beijing 100039 China Institut National de la Recherche Agronomique Climat Sol Environnement 84914 Avignon France College of Information and Electrical Engineering China Agricultural University Beijing 100083 China China Center for Resource Satellite Data and Application Beijing 100830 China

CCD and WFI are payloads in the visible light and near infrared bands on CBERS satellites and they have not been applied widely, especially WFI. This article mainly probes into the potential of these two sensors’ application in the vegetation monitoring and analyses the influences of radiometric calibration, atmosphere conditions and sun-observing geometry, etc. on NDVI obtained from these two sensors respectively. In addition it analyses the effect of the spectral response difference of red and near infrared spectral bands in CCD and WFI sensors on NDVI. Results indicate that radiometric calibration is the most important factor on NDVI, which cannot be applied to vegetation monitoring without radiometric calibration. Results also demonstrate that near surface NDVI is different greatly from that of TOA which change with atmosphere conditions. The study shows that NDVI is also affected by the non-lambertian character of surface and the change of the atmospheric path with the observing geometry. And NDVI of WFI is higher than that of CCD. They are very different because of their spectral difference, but they have a good linear relevant relationship.

关键词： CCD WFI NDVI LAI.

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 {2. of {2. sensing science, Institute of {2. sensing Applications, Chinese Academy of sciences, beijing 100101, China 2. Geography and Environment College, Jiangxi Normal University, Nanchang 33002., 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 state key {2. of {2. sensing science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China Geography and Environment College Jiangxi Normal University Nanchang 330027 China Graduate University Chinese Academy of Sciences Beijing 100039 China beijing Research Institute of Uranium Geology Beijing 100875 China Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 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.

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

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science China(Technological sciences) 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 {2. of {2. sensing science, Jointly Sponsored by the Institute of {2. 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 {2. of {2. sensing science Beijing Normal University Chinese Academy of Sciences Beijing 100101 China Center for National Spaceborne Demonstration Beijing 100101 China Institut National de la Recherche Agronomique Climat Sol Environnement 84914 Avignon France Graduate University Chinese Academy of Sciences Beijing 100039 China China Center for Resource Satellite Data and Application Beijing 100830 China University of Electronic science and Technology of China Chengdu 610054 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.

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 {2. of {2. sensing science, Jointly Sponsored by the Institute of {2. 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 state key {2. of {2. sensing science Beijing Normal University Chinese Academy of Sciences Beijing 100101 China Graduate University Chinese Academy of Sciences Beijing 100039 China Center for National Spaceborne Demonstration Beijing 100101 China Institut National de la Recherche Agronomique Climat Sol Environnement 84914 Avignon France China Center for Resource Satellite Data and Application Beijing 100830 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.

A method for blind separation of components information from mixed pixel

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Progress in Natural science:Materials International 2006年第7期16卷 760-765页

作者： FAN Wenjie and XU Xiru ( Institute of remote sensing and Geographical Information System, Peking University, {2. 100871, China Center of remote sensing and GIS of {2. Normal University, beijing 100875, China) Peking Univ Inst Remote Sensing & Geog Informat Syst Beijing 100871 Peoples R China beijing Normal Univ Ctr Remote Sensing & GIS Beijing 100875 Peoples R China

In the field of remote sensing, it is important to separate the component information from mixed pixel. If the physical process of remote sensing can be expressed by a set of linear equations, the remote sensing information matrix is equal to the weight matrix multiplied by the component information matrix. Generally speaking, the precondition of retrieval of component information matrix is that the weight matrix is known. However, the blind signal separation (BSS) method can separate the matrix unconditionally, whose basic principle is that the additive information needing separation can be achieved from the statistical characteristics contained in a mass of samples in the remotely sensed information matrix. Therefore, the values of the component information matrix and the weight matrix can be estimated. The wave shape of components can be retrieved by BSS, but the amplitude cannot. In this paper, the plant-soil mixed pixels were chosen as the studying targets in this paper to quantitatively separate the component information and solve the uncertainty of BSS. Simulation and field test verify the reliability of the method. Results show that the BSS can be one of the effective methods of mixed pixel separation, and the foreground of application is very promising.

关键词： mixed pixel component information blind signal separation.

Parameter determination to calculate water environmental capacity in Zhangweinan Canal Sub-basin in China

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Journal of Environmental sciences 2010年第6期22卷 904-907页

作者： Yingxia Li ,Ruzhi Qiu,Zhifeng Yang,Chunhui Li,Jingshan Yu state key {2. of Water Environment Simulation,School of Environment,{2. Normal University,{2.,100875,China. state key {2. of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China

Zhangweinan canal sub-basin （ZWN） has the most serious water resource shortage and water pollution problems in north of China. To calculate the water environmental capacity in ZWN, determination methods for design flow rates and degradation coefficients were discussed in this study. Results showed that 90% and 50% hydrological guarantee flow rates were suitable to be the design flow rates for rainy and dry seasons, respectively. Degradation coefficients of CODMn and NH3-N were 0.2. day^-1 and 0.15 day^-1 for branch streams and 0.5 day^-1 and 0.2. day^-1 for mainstreams, respectively in ZWN. With one-dimensional water quality simulation model, water environmental capacities were calculated to be 82.139 tons/yr for CODMn and 2.94 tons/yr for NH3-N in ZWN.

关键词： degradation coefficient design flow rate water environmental capacity Zhangweinan

Change of surface cover greenness in China between 2.00 and 2.10

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

作者： LIU Shuang1,4& GONG Peng1,2.31state key {2. of {2. sensing science, Jointly Sponsored by Institute of {2. sensing Applications of Chinese Academy of sciences,and beijing Normal University, beijing 100101, China 2.nstitute 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, CA9472., USA 4Graduate University of Chinese Academy of sciences, beijing 100049, China state key {2. of {2. 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 2.00 to 2.10 and analyzed their change over China in this *** results showed that an increasing trend of NDVI occurred over 66.84% (OLS fitting) or 64.2.% (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

Effect of rainfall interannual variability on the biomass and soil water distribution in a semiarid shrub community

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science China(Life sciences) 2010年第6期53卷 729-737页

作者： LIU JunShanXU XiaZHANG Yong,TIAN YuQiang & GAO Qiong state key {2. of Earth Surface Processes and Resource Ecology,College of Resources {2. & Technology,beijing Normal University,beijing 100875,China state key {2. of Earth Surface Processes and Resource Ecology College of Resources Science & Technology Beijing Normal University Beijing China

The dynamics of biomass and soil moisture in semiarid land is driven by both the current rainfall and the ecosystem *** on a meta-analysis of existing experiments,an ecosystem model was used to calculate the effect of the rainfall interannual variability on the pattern of biomass and soil moisture in a shrub *** was found that rainfall interannual variability enabled shrubs to be more competitive than grasses,and to maintain the dominant role over a longer *** rainfall interannual variability resulted in complex soil moisture *** soil water recharge in wet years alternated with discharge in drought years.

关键词： rainfall shrub community Artemisia ordosica ecosystem model ecohydrology

Research on the Earth system multi-body force system dynamical model

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science China(Technological sciences) 2006年第Z2期49卷 11-22页

作者： CHEN Xiaofei, BI Siwen, WU Fei & DONG Qianlin state key {2. of {2. sensing science, Jointly Sponsored by the Institute of {2. sensing Applications of Chinese Academy of sciences and beijing Normal University, beijing 100101, China {2. of 3D Information Access and Application of Capital Normal University, beijing 100037, China Chinese Acad Sci Inst Remote Sensing Applicat State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China beijing Normal Univ Beijing 100101 Peoples R China Capital Normal Univ Lab D Informat Access & Applicat 3 Beijing 100037 Peoples R China

This paper presents an overview of the binding force and freedom force of Earth system, and describes force moment to point and line and force system in the Earth system. It introduces the force theory of the Earth system multi-body force system from special or equivalent force system of Earth system mechanics, general force and no-power force of Earth system. Finally it describes the force and moment of nodes of Earth system and provides basic model for the research of the Earth system multi-body dynamics.

关键词： Earth system, multi-body system force, dynamics, basic models.