500米口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)——“中国天眼”举世瞩目,是世界上最大的单口径射电望远镜。如果再建造几个FAST型大射电望远镜,开展联合观测,那么不仅可以进一步提高探测的灵...500米口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)——“中国天眼”举世瞩目,是世界上最大的单口径射电望远镜。如果再建造几个FAST型大射电望远镜,开展联合观测,那么不仅可以进一步提高探测的灵敏度,也可以提高分辨率,从而拓展射电天文研究领域,这正是当前中国射电天文科学家的期盼,FAST型大射电望远镜选址洼地地形搜寻就是为实现这一期盼而开展的前期研究。当前,可以共享的地形数据数字高程模型(digital elevation model,DEM)资源已经实现洲际覆盖,且有不同的地面分辨率供选择;计算机技术发展带来了地形数据DEM处理分析能力大大增强,处理技术不断创新,分析表达实现了可仿真。为此,通过比较分析阿雷西博射电望远镜(Arecibo radio telescope,Arecibo)和FAST望远镜工程结构尺度、台址岩溶洼地地形的形态特点,提出500 m口径望远镜的理想洼地地形条件;在评价分析网络共享DEM地形数据的分辨率和数据质量的基础上,总结认为省级区域大射电望远镜选址以30 m分辨率的ASTER_GDEMV3数据为宜;在贵州全省大型洼地地形搜寻研究中,开发了基于ArcGIS平台提取洼地地形特征参数和拟合填挖方、叠合剖面等定量分析专题模块,归纳了应用ArcGIS主要工具搭建专题模块的关键步骤。研究结果解决了省级区域大型岩溶洼地地形搜寻中的关键技术,并提出了在实际工作中需要注意的几个问题。展开更多
China's designation of the "21 st-century Maritime Silk Road"(MSR) region is of extraordinary significance to its maritime rights, transportation security, and socio-economic development. We developed a ...China's designation of the "21 st-century Maritime Silk Road"(MSR) region is of extraordinary significance to its maritime rights, transportation security, and socio-economic development. We developed a technical framework allowing the use of "big data" derived from the Automatic Identification System(AIS, an automatic ship-tracking network) for two purposes: the accurate mapping of oil tanker trajectories and the creation of heat maps showing the relative use of oil tanker routes and marine shipping chokepoints. We then applied these methods to 1.5 billion AIS records collected within the MSR in 2014 to statistically identify and analyze busy routes, areas, and chokepoints in this strategic region. Our results demonstrate that the proposed framework can provide an effective analysis of oil movements based on large-scale AIS datasets, helping researchers and policy makers better understand the footprint and strategic implications of maritime oil transportation in the MSR region.展开更多
基金supported by the National Key R&D Plan(Grant No.2017YFB0504205)the National Natural Science Foundation of China(Grant Nos.41622109,41371017)
文摘China's designation of the "21 st-century Maritime Silk Road"(MSR) region is of extraordinary significance to its maritime rights, transportation security, and socio-economic development. We developed a technical framework allowing the use of "big data" derived from the Automatic Identification System(AIS, an automatic ship-tracking network) for two purposes: the accurate mapping of oil tanker trajectories and the creation of heat maps showing the relative use of oil tanker routes and marine shipping chokepoints. We then applied these methods to 1.5 billion AIS records collected within the MSR in 2014 to statistically identify and analyze busy routes, areas, and chokepoints in this strategic region. Our results demonstrate that the proposed framework can provide an effective analysis of oil movements based on large-scale AIS datasets, helping researchers and policy makers better understand the footprint and strategic implications of maritime oil transportation in the MSR region.
