Payments for Ecosystem Services(PES)have been studied extensively over the past decade as an important policy tool for coordinating ecological protection and regional socioeconomic development.One of the greatest chal...Payments for Ecosystem Services(PES)have been studied extensively over the past decade as an important policy tool for coordinating ecological protection and regional socioeconomic development.One of the greatest challenges of PES implementation is to understand where to pay,i.e.,spatial targeting,which can directly impact PES effectiveness and efficiency.In this study,we conducted a systematic review of spatial targeting methods based on literature analysis using Citespace.Firstly,peer-reviewed articles related to spatial targeting of PES were selected from the Web of Science database based on keywords.Cases applying PES spatial targeting methods were then chosen and analyzed after all articles were read.In total,70%of the chosen cases focused on improving the compensation efficiency of biodiversity or another single environmental objective,whereas the remaining cases focused on coordinating trade-offs between equity and efficiency or multiple environmental objectives.The main PES spatial targeting approaches included cost-benefit analysis,multi-objective optimization,data envelope analysis and other methods aimed at specific issues.Of these,cost-benefit analysis has been most widely applied at different scales,including county,regional and watershed scales.Significant differences among the different PES spatial targeting methods were found,including in PES spatial targeting dimensions,efficiency optimization approaches and method application conditions.The practice of PES spatial targeting requires the selection of appropriate methods based on contextual biophysical and socioeconomic conditions as well as relevant environmental issues.The combined application of PES spatial targeting methods,compensation willingness of stakeholders and dynamic implementation of PES spatial targeting should be considered in future research.展开更多
Target detection is always an important application in hyperspectral image processing field. In this paper, a spectral-spatial target detection algorithm for hyperspectral data is proposed.The spatial feature and spec...Target detection is always an important application in hyperspectral image processing field. In this paper, a spectral-spatial target detection algorithm for hyperspectral data is proposed.The spatial feature and spectral feature were unified based on the data filed theory and extracted by weighted manifold embedding. The novelties of the proposed method lie in two aspects. One is the way in which the spatial features and spectral features were fused as a new feature based on the data field theory, and the other is that local information was introduced to describe the decision boundary and explore the discriminative features for target detection. The extracted features based on data field modeling and manifold embedding techniques were considered for a target detection task.Three standard hyperspectral datasets were considered in the analysis. The effectiveness of the proposed target detection algorithm based on data field theory was proved by the higher detection rates with lower False Alarm Rates（FARs） with respect to those achieved by conventional hyperspectral target detectors.展开更多
At low SNR cases, the distinction between spatial point-target and interferences as decoys is still a very difficult problem. Based on the characteristics that target and interferences as decoys and noise had differen...At low SNR cases, the distinction between spatial point-target and interferences as decoys is still a very difficult problem. Based on the characteristics that target and interferences as decoys and noise had different radiation intensity and radiation changing frequency, the concept of the equivalent blackbody temperature （EBT） was built and the calculation model of EBT was designed. The model could effectively reduce the interference of the space environment and fully show the radiation differences between point-target and interferences as decoys. It would be very effective in the detection of the target. In order to detect the target, the effective estimator of EBT was designed according to the observed data, and the system error and the variation range of the estimator of EBT were estimated. Finally the multi-frame estimator was designed to improve the estimation stability of EBT, and the use of this estimator would identify the point-target more effectively.展开更多
The imaging plane of inverse synthetic aperture radar （ISAR） is the projection plane of the target. When taking an image using the range-Doppler theory, the imaging plane may have a spatial-variant property, which c...The imaging plane of inverse synthetic aperture radar （ISAR） is the projection plane of the target. When taking an image using the range-Doppler theory, the imaging plane may have a spatial-variant property, which causes the change of scatter＇s projection position and results in migration through resolution cells, In this study, we focus on the spatial-variant property of the imaging plane of a three-axis-stabilized space target. The innovative contributions are as follows. 1） The target motion model in orbit is provided based on a two-body model. 2） The instantaneous imaging plane is determined by the method of vector analysis. 3） Three Euler angles are introduced to describe the spatial-variant property of the imaging plane, and the image quality is analyzed. The simulation results confirm the analysis of the spatial-variant property. The research in this study is significant for the selection of the imaging segment, and provides the evidence for the following data processing and compensation algorithm.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(Grant No.2019QZKK0307)the China National Social Science Funding of Major Projects(Grant No.18VSJ100)National Natural Science Foundation of China(Grant No.41925005).
文摘Payments for Ecosystem Services(PES)have been studied extensively over the past decade as an important policy tool for coordinating ecological protection and regional socioeconomic development.One of the greatest challenges of PES implementation is to understand where to pay,i.e.,spatial targeting,which can directly impact PES effectiveness and efficiency.In this study,we conducted a systematic review of spatial targeting methods based on literature analysis using Citespace.Firstly,peer-reviewed articles related to spatial targeting of PES were selected from the Web of Science database based on keywords.Cases applying PES spatial targeting methods were then chosen and analyzed after all articles were read.In total,70%of the chosen cases focused on improving the compensation efficiency of biodiversity or another single environmental objective,whereas the remaining cases focused on coordinating trade-offs between equity and efficiency or multiple environmental objectives.The main PES spatial targeting approaches included cost-benefit analysis,multi-objective optimization,data envelope analysis and other methods aimed at specific issues.Of these,cost-benefit analysis has been most widely applied at different scales,including county,regional and watershed scales.Significant differences among the different PES spatial targeting methods were found,including in PES spatial targeting dimensions,efficiency optimization approaches and method application conditions.The practice of PES spatial targeting requires the selection of appropriate methods based on contextual biophysical and socioeconomic conditions as well as relevant environmental issues.The combined application of PES spatial targeting methods,compensation willingness of stakeholders and dynamic implementation of PES spatial targeting should be considered in future research.
文摘Target detection is always an important application in hyperspectral image processing field. In this paper, a spectral-spatial target detection algorithm for hyperspectral data is proposed.The spatial feature and spectral feature were unified based on the data filed theory and extracted by weighted manifold embedding. The novelties of the proposed method lie in two aspects. One is the way in which the spatial features and spectral features were fused as a new feature based on the data field theory, and the other is that local information was introduced to describe the decision boundary and explore the discriminative features for target detection. The extracted features based on data field modeling and manifold embedding techniques were considered for a target detection task.Three standard hyperspectral datasets were considered in the analysis. The effectiveness of the proposed target detection algorithm based on data field theory was proved by the higher detection rates with lower False Alarm Rates（FARs） with respect to those achieved by conventional hyperspectral target detectors.
文摘At low SNR cases, the distinction between spatial point-target and interferences as decoys is still a very difficult problem. Based on the characteristics that target and interferences as decoys and noise had different radiation intensity and radiation changing frequency, the concept of the equivalent blackbody temperature （EBT） was built and the calculation model of EBT was designed. The model could effectively reduce the interference of the space environment and fully show the radiation differences between point-target and interferences as decoys. It would be very effective in the detection of the target. In order to detect the target, the effective estimator of EBT was designed according to the observed data, and the system error and the variation range of the estimator of EBT were estimated. Finally the multi-frame estimator was designed to improve the estimation stability of EBT, and the use of this estimator would identify the point-target more effectively.
基金Project supported by the National Natural Science Foundation of China(Grant No.61401024)the Shanghai Aerospace Science and Technology Innovation Foundation,China(Grant No.SAST201240)the Basic Research Foundation of Beijing Institute of Technology(Grant No.20140542001)
文摘The imaging plane of inverse synthetic aperture radar （ISAR） is the projection plane of the target. When taking an image using the range-Doppler theory, the imaging plane may have a spatial-variant property, which causes the change of scatter＇s projection position and results in migration through resolution cells, In this study, we focus on the spatial-variant property of the imaging plane of a three-axis-stabilized space target. The innovative contributions are as follows. 1） The target motion model in orbit is provided based on a two-body model. 2） The instantaneous imaging plane is determined by the method of vector analysis. 3） Three Euler angles are introduced to describe the spatial-variant property of the imaging plane, and the image quality is analyzed. The simulation results confirm the analysis of the spatial-variant property. The research in this study is significant for the selection of the imaging segment, and provides the evidence for the following data processing and compensation algorithm.
