Using three-phase remote sensing images of China-Brazil Earth Resources Satellite 02B (CBERS02B) and Landsat-5 TM, tobacco field was extracted by the analysis of time series image based on the different phenological c...Using three-phase remote sensing images of China-Brazil Earth Resources Satellite 02B (CBERS02B) and Landsat-5 TM, tobacco field was extracted by the analysis of time series image based on the different phenological characteristics between tobacco and other crops. The spectral characteristics of tobacco and corn in luxuriant growth stage are very similar, which makes them difficult to be distinguished using a single-phase remote sensing image. Field film after tobacco seedlings transplanting can be used as significant sign to identify tobacco. Remote sensing interpre- tation map based on the fusion image of TM and CBERS02B's High-Resolution (HR) camera image was used as stan- dard reference material to evaluate the classification accuracy of Spectral Angle Mapper (SAM) and Maximum Like- lihood Classifier (MLC) for time series image based on full samples test method. SAM has higher classification accu- racy and stability than MLC in dealing with time series image. The accuracy and Kappa of tobacco coverage extracted by SAM are 83.4% and 0.692 respectively, which can achieve the accuracy required by tobacco coverage measurement in a large area.展开更多
Three kinds of application of nonlinear fractal theory in the turbulent combustion werediscussed, which included the multiscale measurement, the measure analysis and the correlative dimension of chaotic attractors in ...Three kinds of application of nonlinear fractal theory in the turbulent combustion werediscussed, which included the multiscale measurement, the measure analysis and the correlative dimension of chaotic attractors in temperature time series signals. This work not onlyrevealed the spatial fractal character in combustion, but also acquired the correlation andtemporal scale of the turbulent flunctuation.展开更多
Satellite-based wetland mapping faces challenges due to the high spatial heterogeneity and dynamic characteristics of seasonal wetlands.Although normalized difference vegetation index(NDVI)time series(NTS)shows great ...Satellite-based wetland mapping faces challenges due to the high spatial heterogeneity and dynamic characteristics of seasonal wetlands.Although normalized difference vegetation index(NDVI)time series(NTS)shows great potential in land cover mapping and crop classification,the effectiveness of various NTS with different spatial and temporal resolution has not been evaluated for seasonal wetland classification.To address this issue,we conducted comparisons of those NTS,including the moderate-resolution imaging spectroradiometer(MODIS)NTS with 500 m resolution,NTS fused with MODIS and Landsat data(MOD_LC8-NTS),and HJ-1 NDVI compositions(HJ-1-NTS)with finer resolution,for wetland classification of Poyang Lake.Results showed the following:(1)the NTS with finer resolution was more effective in the classification of seasonal wetlands than that of the MODIS-NTS with 500-m resolution and(2)generally,the HJ-1-NTS performed better than that of the fused NTS,with an overall accuracy of 88.12%for HJ-1-NTS and 83.09%for the MOD_LC8-NTS.Future work should focus on the construction of satellite image time series oriented to highly dynamic characteristics of seasonal wetlands.This study will provide useful guidance for seasonal wetland classification,and benefit the improvements of spatiotemporal fusion models.展开更多
基金国家863课题"全球森林生物量和碳储量遥感估测关键技术(编号:2012AA12A306)"亚太森林恢复与可持续管理网络项目"Forest Cover and Aboveground Biomass Mapping in the Greater Mekong Subregion and Malaysia(编号:2011PA004)"资助
基金Under the auspices of China Postdoctoral Science Foundation (No. 20080430586, 20070420018)National Natural Science Foundation of China (No. 40801161, 40801172)Sino US International Cooperation in Science and Technology (No. 2007DFA20640)
文摘Using three-phase remote sensing images of China-Brazil Earth Resources Satellite 02B (CBERS02B) and Landsat-5 TM, tobacco field was extracted by the analysis of time series image based on the different phenological characteristics between tobacco and other crops. The spectral characteristics of tobacco and corn in luxuriant growth stage are very similar, which makes them difficult to be distinguished using a single-phase remote sensing image. Field film after tobacco seedlings transplanting can be used as significant sign to identify tobacco. Remote sensing interpre- tation map based on the fusion image of TM and CBERS02B's High-Resolution (HR) camera image was used as stan- dard reference material to evaluate the classification accuracy of Spectral Angle Mapper (SAM) and Maximum Like- lihood Classifier (MLC) for time series image based on full samples test method. SAM has higher classification accu- racy and stability than MLC in dealing with time series image. The accuracy and Kappa of tobacco coverage extracted by SAM are 83.4% and 0.692 respectively, which can achieve the accuracy required by tobacco coverage measurement in a large area.
文摘Three kinds of application of nonlinear fractal theory in the turbulent combustion werediscussed, which included the multiscale measurement, the measure analysis and the correlative dimension of chaotic attractors in temperature time series signals. This work not onlyrevealed the spatial fractal character in combustion, but also acquired the correlation andtemporal scale of the turbulent flunctuation.
基金the Major Special Project-the China High-Resolution Earth Observation System[grant number 30-Y20A37-9003-15/17]The National Natural Science Foundation of China[grant number 41271423].
文摘Satellite-based wetland mapping faces challenges due to the high spatial heterogeneity and dynamic characteristics of seasonal wetlands.Although normalized difference vegetation index(NDVI)time series(NTS)shows great potential in land cover mapping and crop classification,the effectiveness of various NTS with different spatial and temporal resolution has not been evaluated for seasonal wetland classification.To address this issue,we conducted comparisons of those NTS,including the moderate-resolution imaging spectroradiometer(MODIS)NTS with 500 m resolution,NTS fused with MODIS and Landsat data(MOD_LC8-NTS),and HJ-1 NDVI compositions(HJ-1-NTS)with finer resolution,for wetland classification of Poyang Lake.Results showed the following:(1)the NTS with finer resolution was more effective in the classification of seasonal wetlands than that of the MODIS-NTS with 500-m resolution and(2)generally,the HJ-1-NTS performed better than that of the fused NTS,with an overall accuracy of 88.12%for HJ-1-NTS and 83.09%for the MOD_LC8-NTS.Future work should focus on the construction of satellite image time series oriented to highly dynamic characteristics of seasonal wetlands.This study will provide useful guidance for seasonal wetland classification,and benefit the improvements of spatiotemporal fusion models.
