首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2篇
  免费   0篇
  国内免费   1篇
航空   2篇
航天技术   1篇
  2017年   1篇
  1993年   1篇
  1982年   1篇
排序方式: 共有3条查询结果,搜索用时 15 毫秒
1
1.
Airports are being developed and expanded rapidly in China to accommodate and pro-mote a growing aviation market. The future Beijing Daxing International Airport (DAX) will serve as the central airport of the JingJinJi megaregion, knitting the Beijing, Tianjin, and Hebei regions together. DAX will be a busy airport from its inception, relieving congestion and accommodating growth from Beijing Capital International Airport (PEK), currently the second busiest airport in the world in passengers moved. We aim to model terminal airspace designs and possible conflicts in the future Beijing Multi-Airport System (MAS). We investigate standard arrival procedures and mathematically model current and future arrival trajectories into PEK and DAX by collecting large quantities of publicly available track data from historical arrivals operating within the Beijing terminal airspace. We find that (1) trajectory models constructed from real data capture aberrations and deviations from standard arrival procedures, validating the need to incorporate data on histor-ical trajectories with standard procedures when evaluating the airspace and (2) given all existing constraints, DAX may be restricted to using north and east arrival flows, constraining the capacity required to handle the increases in air traffic demand to Beijing. The results indicate that the termi-nal airspace above Beijing, and the future JingJinJi region, requires careful consideration if the full capacity benefits of the two major airports are to be realized.  相似文献   
2.
Project Trinidad     
The first intercontinental satellite communication link, which involved the NASA Echo I balloon, a transmitting station on the Island of Trinidad, and a receiving station at Floyd, NY, is discussed. Rome Air Development Center (RADC) experimental stations were set up using a great deal of ingenuity and makeshift equipment and on a very small budget. Much of the equipment was salvaged from unrelated systems, while some was hand-built for this project. The implementation of the system, the testing of the system using moon bounce, the first orbital launch of the Echo I balloon, and the early difficulties encountered in the project are reviewed  相似文献   
3.
This report summarizes a major paper reviewing the progression of work using Landsat for land use and agricultural monitoring in Canada since 1973. From the launch of Landsat to the present, the focus has moved from using simple visual techniques for interpretation of photographic products to the use of conceptually simple methods which now employ the power of special-purpose image analysis hardware and the standard geometrically corrected products available in Canada. Outlined in the major paper are studies on urban growth, large area land use mapping, crop studies (related to both crop area estimates and erosion potential), assessment of changes in vegetation vigour and clearing of land in areas which were devoted to both dry land farming and forestry. This report emphasizes developments in land use studies.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号