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Novel polarimetric detector for target detection in heterogeneous clutter

Journal of systems Engineering and Electronics 2016年第6期27卷 1135-1141页

作者： Xu Cheng Longfei Shi Yuliang Chang Yongzhen Li Xuesong Wang State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System College of Electronic Science and Engineering National University of Defense Technology

A detection of static or slowly moving targets in the inhomogeneous clutter of polarimetric radar is researched and a new detector without exploiting the training set is developed, which has a good performance against the inhomogeneous clutter. The decision rule ensures the constant false alarm rate (CFAR) with respect to the disturbance covariance matrix. Numerical results show the robustness of the proposed method against the inhomogeneous clutter. © 2016 Beijing Institute of Aerospace information.

关键词： Clutter (information theory) Covariance matrix Numerical methods Polarimeters Radar Radar clutter Radar signal processing Signal processing

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Potential Challenges and Food Security Responses to Climate Change in China and Mongolia in the Post-COP28 Era

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Journal of resources and Ecology 2025年第1期16卷 22-35页

作者： CHEN Jiannan Faith Ka Shun CHAN WANG Jiayu FENG Meili WANG Zilin Ochir ALTANSUKH SHAO Yating LI Pengfei WANG School of Human Settlements and Civil Engineering Xi’an Eurasia UniversityXi’an 710054China College of Geomatics Xi’an University of Science and TechnologyXi’an 710054China School of Geographical Sciences University of Nottingham Ningbo ChinaNingboZhejiang 315100China Water@Leeds Research Institute and School of Geography University of LeedsLeeds LS29JTUK Research Centre for Intelligent Management&Innovation Development/Research Base for Shenzhen Municipal Policy&Development Southern University of Science and TechnologyShenzhenGuangdong 518000China Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamenFujian 361021China Department of Environment and Forest Engineering School of Engineering and Technology and Environmental Engineering LaboratoryNational University of MongoliaUlaanbaatar 14201Mongolia State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

After the COP28 Conference,many countries are increasingly concerned about their future practices regarding food *** North Asia,the Northeast China is the major food production base for the *** the border,the economy of Mongolia is heavily reliant on agricultural production and animal *** recent years,climatic extremes such as droughts and floods,combined with human-induced overgrazing,have posed alarming threats to food *** review illustrates the challenges and constraints these two countries are facing due to climate changes and summarizes the existing measures and established programs in both ***,we develop the“climate resilient agriculture”(CRA)framework for improving agricultural *** framework emphasizes the importance of international institutions,such as the World Bank,and developed countries to provide more financial and technological support to bolster climate resilience in Northern ***,we conclude by encouraging cross-border co-production and collaborations among governments to implement the CRA framework to tackle future climatic challenges.

关键词： agricultural sensitivity climatic extremes climate resilient agriculture(CRA) food security China and Mongolia

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A new cloud base height retrieval method and its application in cloudy-sky surface downwelling longwave radiation estimation

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IEEE Transactions on Geoscience and Remote Sensing 2025年 63卷

作者： Jiang, Yun Tang, Bo-Hui Li, Zhao-Liang Zhang, Huanyu Chinese Academy of Sciences State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources Research Beijing100101 China Kunming University of Science and Technology Faculty of Land Resource Engineering Kunming650093 China Yunnan Key Laboratory of Quantitative Remote Sensing Kunming650093 China Yunnan International Joint Laboratory for Integrated Sky-Ground Intelligent Monitoring of Mountain Hazards Kunming650093 China Chinese Academy of Agricultural Sciences State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China Institute of Agricultural Resources and Regional Planning Beijing100081 China

Cloud base height (CBH) is crucial for determining cloud radiation effects, and uncertainty in CBH retrieval can lead to significant errors in the estimation of surface downwelling longwave radiation (SDLR) under cloudy-sky conditions. This study proposes a new CBH retrieval model utilizing top of atmosphere (TOA) reflectance and brightness temperature observations from the Fengyun-4A (FY-4A) satellite, employing the random forest algorithm. The accurately retrieved CBH is then used to estimate cloudy-sky SDLR, accounting for the radiative effects of the entire cloud layer. The CBH retrieval algorithm relies solely on TOA observations and cloud top parameter information, enabling CBH retrieval even in the absence of cloud optical thickness. The verification results indicate that the newly proposed CBH retrieval algorithm achieves good accuracy, with a bias of ﹣0.19 km and an RMSE of 1.52 km. Compared to existing studies, the new algorithm performs well in both water cloud and ice cloud phases. Based on the accurately retrieved CBH, this study employs an estimation scheme that uses cloud effective temperature to characterize the radiation contribution of the entire cloud layer, enabling accurate estimation of cloudy-sky SDLR. Ground-based measurements from the Baseline Surface Radiation Network (BSRN) and the National Tibetan Plateau Data Center (TPDC) sites were used to validate the SDLR estimation scheme. The results showed that the cloudy-sky SDLR estimated using the retrieved CBH achieved reasonable accuracy, with a bias of 7.15 W/m2 and an RMSE of 27.42 W/m2 © 1980-2012 IEEE.

关键词： Radiation damage

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Integrated spatial sampling modeling of geospatial data

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Science China Earth Sciences 2004年第3期47卷 201-208页

作者： LI Lianfa WANG Jinfeng State Key Laboratory of Resources and Environment Information System Institute of Geography Science & Natural Resources Research Chinese Academy of Sciences Beijing100101 China State Key Laboratory of Resources and Environment Information System Institute of Geography Science & Natural Resources Research Chinese Academy of Sciences Beijing100101 China

Spatial sampling is a necessary and important method for extracting geospatial data and its methodology directly affects the geo-analysis results. Counter to the deficiency of sepa-rate models of spatial sampling, this article analyzes three crucial elements of spatial sampling (frame, correlation and decision diagram) and induces its general integrated model. The program of Spatial Sampling Integration (SSI) has been developed with Component Object Model (COM) to realize the general integrated model. In two practical applications, i.e. design of the monitoring network of natural disasters and sampling survey of the areas of non-cultivated land, SSI has produced accurate results at less cost, better realizing the cost-effective goal of sampling toward the geo-objects with spatial correlation. The two cases exemplify expanded application and convenient implementation of the general integrated model with inset components in an inte-grated environment, which can also be extended to other modeling of spatial analysis.

关键词： spatial sampling, general integrated modeling, component object, practical application.

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Improved statistical sparse decomposition principle method for underdetermined blind source signal recovery

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The Journal of China Universities of Posts and Telecommunications 2019年第6期26卷 94-102页

作者： Wang Chuanchuan Zeng Yonghu Wang Liandong Fu Weihong State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System Luoyang 471003China State Key Laboratory of Integrated Services Networks Xidian UniversityXi'an 710071China

Aiming at the statistical sparse decomposition principle(SSDP) method for underdetermined blind source signal recovery with problem of requiring the number of active signals equal to that of the observed signals, which leading to the application bound of SSDP is very finite, an improved SSDP(ISSDP) method is proposed. Based on the principle of recovering the source signals by minimizing the correlation coefficients within a fixed time interval, the selection method of mixing matrix’s column vectors used for signal recovery is modified, which enables the choose of mixing matrix’s column vectors according to the number of active source signals self-adaptively. By simulation experiments, the proposed method is validated. The proposed method is applicable to the case where the number of active signals is equal to or less than that of observed signals, which is a new way for underdetermined blind source signal recovery.

关键词： underdetermined blind source separation signal recovery ISSDP

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How many trees are there in China?

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Science Bulletin 2025年第7期70卷 1076-1079页

作者： Kai Cheng Haitao Yang Yuling Chen Zekun Yang Yu Ren Yixuan Zhang Danyang Lin Weiyan Liu Guoran Huang Jiachen Xu Mengxi Chen Zhiyong Qi Guangcai Xu Shengli Tao Hongcan Guan Qin Ma Huawei Wan Tianyu Hu Yanjun Su Zhiheng Wang Keping Ma Qinghua Guo Institute of Remote Sensing and Geographic Information System School of Earth and Space SciencesPeking UniversityBeijing 100871China State Forestry and Grassland Administration Key Laboratory of Forest Resources&Environmental Management Beijing Forestry UniversityBeijing 100083China College of Forestry Southwest Forestry UniversityKunming 650224China Beijing Green Valley Technology Co. Ltd.Haidian DistrictBeijing 100091China Institute of Ecology College of Urban and Environmental SciencesPeking UniversityBeijing 100871China School of Tropical Agriculture and Forestry Hainan UniversityHaikou 570228China School of Geography Nanjing Normal UniversityNanjing 210023China Satellite Environmental Application Center of Ministry of Ecology and Environment Beijing 100094China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China University of Chinese Academy of Sciences Beijing 100049China

Accurate quantification of tree populations within regions is critical for evaluating forest ecosystem conditions and developing effective forest management strategies[1].High-quality tree census data,collected through field surveys and remote sensing technologies,is fundamental to China's sustainable development and environmental conservation *** data facilitates the monitoring of forest structural changes,carbon sequestration dynamics,and ecosystem health ***,China maintains the world's largest managed forest area,achieved through comprehensive national afforestation and reforestation programs[2,3].Consequently,precise tree enumeration is crucial for formulating effective forest management policies,monitoring and protecting wildlife habitats,and preventing natural disasters in China.

关键词： remote sensing technologiesis quantification tree populations forest management developing effective forest management strategies high quality field surveys monitoring forest structural changescarbon sequestration dynamicsand evaluating forest ecosystem conditions tree population

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Rural land use spatial allocation in the semiarid loess hilly area in China:Using a Particle Swarm Optimization model equipped with multi-objective optimization techniques

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Science China Earth Sciences 2012年第7期55卷 1166-1177页

作者： LIU YaoLin LIU DianFeng LIU YanFang HE JianHua JIAO LiMin CHEN YiYun HONG XiaoFeng School of Resource and Environment Science Wuhan UniversityWuhan 430079China Ministry of Education Key Laboratory of Geographic Information System Wuhan UniversityWuhan 430079China

Semiarid loess hilly areas in China are enduring a series of environmental conflicts between urban expansion,cultivated land conservation,soil erosion and water shortage,and require land use allocation to reconcile these environmental *** argue that the optimized spatial allocation of rural land use can be achieved by a Particle Swarm Optimization (PSO) model in conjunction with multi-objective optimization *** study focuses on Yuzhong County of Gangsu Province in China,a typical catchment on the Loess Plateau,and proposes a land use spatial optimization *** model maximizes land use suitability and spatial compactness based on a variety of constraints,*** land use structure and restrictive areas,and employs an improved PSO algorithm equipped with a determinant initialization method and a dynamic weighted aggregation (DWA) method to obtain the optimized land use spatial *** results suggest that (1) approximately 4% of land use should be reallocated and these changes would alleviate the environmental conflicts in the study area;(2) the major reshuffling is slope farmland and newly added construction and cultivated land,whereas the unchanged areas are largely forests and basic farmland;and (3) the PSO is capable of optimizing rural land use allocation,and the determinant initialization method and DWA can improve the performance of the PSO.

关键词： spatial allocation rural land use particle swarm optimization multi-objective optimization Loess Plateau

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Contrasting temporal dynamics of land surface temperature responses to different types of forest loss

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Innovation 2025年

作者： Li, Jing Li, Zhao-Liang Liu, Xiangyang Li, Yitao Liu, Meng You, Nanshan Wu, Hua He, Lei Si, Menglin Tang, Ronglin Zhou, Chenghu Zhao, Wei Duan, Si-Bo Leng, Pei Liu, Wenqi Zhao, Enyu Tang, Bo-Hui Jin, Zhenong State Key Laboratory of Efficient Utilization of Arable Land in China Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing100081 China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China Key Lab for Resources Use and Environmental Remediation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China School of Resources and Environment University of Electronic Science and Technology of China Chengdu610054 China Guangzhou Institute of Geography Guangdong Academy of Sciences Guangzhou510070 China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu610041 China Department of Geography Oklahoma State University StillwaterOK74078 United States College of Information Science and Technology Dalian Maritime University Dalian116026 China Faculty of Land Resource Engineering Kunming University of Science and Technology Kunming650093 China Department of Bioproducts and Biosystems Engineering University of Minnesota St. PaulMN55108 United States Institute of Ecology College of Urban and Environmental Science Peking University Beijing100871 China Peking University Beijing100871 China

Forest loss impacts local climate through biophysical processes. However, our understanding of this impact remains limited due to the neglect of its temporal dynamics. Using a space-and-time scheme that incorporates a change-detection method, we assess the dynamics of land surface temperature (LST) responses to various forest-loss types. Globally, LST increased by 0.12 K one year after forest loss, followed by a decreasing trend of −0.14 K per decade. Deforestation driven by commodity production and urbanization results in persistent warming, while forest disturbances such as shifting agriculture, forestry, and fire trigger diverse response dynamics with significant spatial variation due to differences in subsequent vegetation recovery. These disturbances cause attenuated warming in low and mid-latitudes, while, in the boreal zone, contrasting dynamics are observed: shifting agriculture causes attenuated cooling, whereas forestry and fire result in enhanced cooling. In addition to amplifying the amplitude of the LST seasonal cycle, forest loss also shifts the seasonal phase, which has not been previously reported. These findings demonstrate that climate feedback from forest loss is climate specific, loss-type dependent, and time varying, providing new insights for the development of local climate policies. © 2025 The Author(s)

关键词： Forest ecology

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Suitability Evaluation of Rural Settlements Based on Accessibility of Production and Living： A Case Study of Tingzu Town in Hubei Prov- ince of China

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Chinese Geographical Science 2016年第4期26卷 550-565页

作者： LIU Yaolin YE Qingqing LI Jiwei KONG Xuesong JIAO Limin School of Resource and Environment Science Wuhan University Wuhan 430079 China Key Laboratory of Geographic Information System Ministry of Education Wuhan University Wuhan 430079 China

Rural settlements are the main carriers of agriculture, rural areas and farmers; thus, optimizing the production and living space of rural settlements is highly significant to rural development. Taking the effective allocation of resources as the starting point, a suitability evaluation system of rural settlements, based on accessibility of production and living, was proposed in this study to provide scientific basis for the optimization of production and living space. The accessibility of production and living was measured by an im- proved two-step floating catchment area method, which considered proximity and availability based on the inclination of rural residents. The suitability evaluation system consisted of traditional suitability evaluation and newly proposed limiting factor identification based on the loss score proportion of suitability. Tingzu Town of Hubei Province, China, was chosen as the case study area. Based on the re- suits of the suitability evaluation system, corresponding suggestions on rural land consolidation, industry division, as well as the layout of health care and education facilities were proposed to optimize the production and living space of rural settlements in Tingzu Town. It is found that the suitability evaluation based on accessibility of production and living is more scientific and accurate than the traditional ones which significantly overestimate production and living convenience. Moreover, the limiting factor identification can help us put forward suggestions according to local conditions and bring about the highly targeted optimization of production and living space of rural settlements.

关键词： rural settlements suitability evaluation accessibility of production and living two-step floating catchment area (2SFCA)method limiting factor identification Tingzu Town

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High-precision inversion of vegetation parameters in the AI era: Integrating hyperspectral remote sensing and deep learning

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Innovation 2025年

作者： Hu, Jinkang Peng, Dailiang Chen, Jing M. Huete, Alfredo R. Yu, Le Lou, Zihang Cheng, Enhui Yang, Xuan Zhang, Bing Key Laboratory of Digital Earth Science Aerospace Information Research Institute Chinese Academy of Sciences Beijing100094 China International Research Center of Big Data for Sustainable Development Goals Beijing100094 China College of Resource and Environment University of Chinese Academy of Sciences Beijing100094 China School of Geographical Sciences Fujian Normal University Fuzhou350117 China Department of Geography and Planning University of Toronto TorontoONM5S 3G3 Canada School of Life Sciences University of Technology Sydney UltimoNSW2007 Australia Department of Earth System Science Ministry of Education Key Laboratory for Earth System Modeling Institute for Global Change Studies Tsinghua University Beijing100084 China Institute of Agricultural Remote Sensing and Information Technology Application College of Environmental and Resource Sciences Zhejiang University Hangzhou310058 China China Remote Sensing Satellite Ground Station Aerospace Information Research Institute Chinese Academy of Sciences Beijing100094 China

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