This paper proposed an efficient method of image overlapping relationship analysis based on spatial index of KD tree fast search for disordered and large-scale asteroid images.In this study,the image data from asteroi...This paper proposed an efficient method of image overlapping relationship analysis based on spatial index of KD tree fast search for disordered and large-scale asteroid images.In this study,the image data from asteroid exploration missions such as Bennu,Vesta,and Ryugu were used for experiments,and the proposed image matching pairs determination algorithm was comprehensively compared with the corresponding modules of USGS ISIS in order to evaluate its performance in terms of efficiency and accuracy.The results show that when processing more than a thousand images,the proposed method greatly improves the efficiency of acquiring image matching pairs while ensuring the correctness of image overlapping relationships and accuracy of bundle adjustment.At the same time,according to the obtained image matching pairs,images that meet the requirements of Stereo Photoclinometry can be quickly selected,effectively improving the quality of 3D reconstruction models of asteroid images.展开更多
Rice planted in southern China accounts for 94% of the total in sown acreage and 88% of the total in production, which matters a lot to Chinese food security. However, due to the prolonged conflict between water avail...Rice planted in southern China accounts for 94% of the total in sown acreage and 88% of the total in production, which matters a lot to Chinese food security. However, due to the prolonged conflict between water availability and rice growth in spatial/temporal distribu- tion, rice production suffers from seasonal drought at acreage of 16%-22%, which compro- mises food production capacity and food security. Focusing on the spatial distribution of seasonal drought with rice and the practices to adapt to it, and based on an analysis of bal- anced water supply for and demand by rice at a growing season scale during 1981-2030, this paper assesses the changing seasonal drought in the process of rice production under the changing climate in the future, and identifies general rice re-cultivation options for climate change adaptation. Some conclusions can be drawn as follows. （1） Rice suggests a decline in seasonal drought, with early season rice （early rice hereafter） by 12,500 km2, middle season rice （middle rice） by 80,000 km2, and in particular late season rice （late rice） by 25,000 km2, which accounts for almost 20% of its cultivated acreage. It is indicated that due to climate change, seasonal drought in major rice producing areas tends to alleviate in general, late season rice in particular. （2） Future climate change brings about a significant impact on the spatial/temporal distribution of water resources in rice producing areas in China. Based on ＇pre-designed＇ adaptation actions for rice-re-cultivation, the rice cultivation pattern undergoes a significant alteration between 1981-2000 and 2001-2030. In eastern Guizhou and western Hunan, the pattern of single early plus single dry farming is changed into double cropping. In eastern Hunan, the pattern of dry cropping is changed into single early plus single dry farming In northern Anhui, the pattern of dry farming cropping is changed into middle rice. All this is aimed at a potential adequate availability of water for rice production in the future. （3） Rice re-cultivation patterns developed in this paper help re-balance water demand and supply for rice growth using the spatial analysis tool to adapt rice growth to the changing water avail- ability from spatial perspective, and come up with rice producer-friendly re-cultivation options in response to climate change.展开更多
基金Space Optoelectronic Measurement and Perception Lab(LabSOMP-2023-07)the National Natural Science Foundation ofChina(42241147)+1 种基金the State Key Laboratory of Geo-Information Engineering(SKLGIE2021-Z-3-1)and the Open Program of Collaborativeinnovation Center of Geo-information(2023C002)。
文摘This paper proposed an efficient method of image overlapping relationship analysis based on spatial index of KD tree fast search for disordered and large-scale asteroid images.In this study,the image data from asteroid exploration missions such as Bennu,Vesta,and Ryugu were used for experiments,and the proposed image matching pairs determination algorithm was comprehensively compared with the corresponding modules of USGS ISIS in order to evaluate its performance in terms of efficiency and accuracy.The results show that when processing more than a thousand images,the proposed method greatly improves the efficiency of acquiring image matching pairs while ensuring the correctness of image overlapping relationships and accuracy of bundle adjustment.At the same time,according to the obtained image matching pairs,images that meet the requirements of Stereo Photoclinometry can be quickly selected,effectively improving the quality of 3D reconstruction models of asteroid images.
基金National Key Technology Research & Development Program, No.2012BAC19B01
文摘Rice planted in southern China accounts for 94% of the total in sown acreage and 88% of the total in production, which matters a lot to Chinese food security. However, due to the prolonged conflict between water availability and rice growth in spatial/temporal distribu- tion, rice production suffers from seasonal drought at acreage of 16%-22%, which compro- mises food production capacity and food security. Focusing on the spatial distribution of seasonal drought with rice and the practices to adapt to it, and based on an analysis of bal- anced water supply for and demand by rice at a growing season scale during 1981-2030, this paper assesses the changing seasonal drought in the process of rice production under the changing climate in the future, and identifies general rice re-cultivation options for climate change adaptation. Some conclusions can be drawn as follows. （1） Rice suggests a decline in seasonal drought, with early season rice （early rice hereafter） by 12,500 km2, middle season rice （middle rice） by 80,000 km2, and in particular late season rice （late rice） by 25,000 km2, which accounts for almost 20% of its cultivated acreage. It is indicated that due to climate change, seasonal drought in major rice producing areas tends to alleviate in general, late season rice in particular. （2） Future climate change brings about a significant impact on the spatial/temporal distribution of water resources in rice producing areas in China. Based on ＇pre-designed＇ adaptation actions for rice-re-cultivation, the rice cultivation pattern undergoes a significant alteration between 1981-2000 and 2001-2030. In eastern Guizhou and western Hunan, the pattern of single early plus single dry farming is changed into double cropping. In eastern Hunan, the pattern of dry cropping is changed into single early plus single dry farming In northern Anhui, the pattern of dry farming cropping is changed into middle rice. All this is aimed at a potential adequate availability of water for rice production in the future. （3） Rice re-cultivation patterns developed in this paper help re-balance water demand and supply for rice growth using the spatial analysis tool to adapt rice growth to the changing water avail- ability from spatial perspective, and come up with rice producer-friendly re-cultivation options in response to climate change.
