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基础地理数据是国家战略性基础信息资源,是信息化建设的数据框架平台,在政府决策、国民经济各部门和大众生活中有着越来越广泛的应用.然而,基础地理数据在其定义、范围、特性等方面至今尚不十分明确,在应用等方面存在一系列的问题,本文主要就这几个方面的问题进行了探讨. 相似文献
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基础地理数据的生命力在于其现势性和准确性,本文结合广东省数字城市基础地理数据的更新升级工作,通过分析各类已有数据资料,探讨了基础地理数据的更新原则、方法和技术体系,力争为基础地理数据更新等同类工作提供参考。 相似文献
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随着地理空间信息资源建设的不断推进和广泛应用,吉林市基础数据平台的工作重心正在由初始的数据建库工作向数据更新转变。本文主要论述了吉林市基础数据平台的更新技术理论及方法,并阐述了其工作流程和实际意义。 相似文献
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城市地理空间基础数据作为各城市各专题系统和综合系统的空间定位基础和公共要素基础,基础地理信息数据库的生命力在于其数据的现势性和准确性,数据库建立后的更新维护非常重要。本文通过佛山市"基于数字城市建设的"一张图"应用模式研究"成果在顺德区具体应用阐述城市基础地理信息矢量数据的动态更新。 相似文献
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李斌 《测绘与空间地理信息》2014,(3):143-144,148
由于技术与国家数据标准的不完善,导致许多早期地形图数据很难满足GIS专题信息提取、数据挖掘与应用的要求,为节约资金充分利用现有的数据资源,对这些数据进行加工整理,使其满足当前基础地理信息数据库建设和应用的需求具有重要的现实意义。本文结合新疆1∶10 000基础地理信息数据加工整理项目,描述了加工整理1∶10 000基础地理信息数据的方法与过程,总结了其中的难点以及解决方法。 相似文献
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数据是智慧景区服务平台的核心与基础,服务平台要发挥其作用,首先要合理确定基础数据的内容和质量要求。本文以天地图·五大连池——智慧景区服务平台基础测绘工程项目为例,介绍了关于基础数据生产中的技术指标和规格,详述了总体技术路线及工艺流程,并对基础数据的质量控制进行了详细说明。 相似文献
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介绍了丽水市户外广告管理地理信息系统的建设框架及建设情况,论述了其依托的基础地理数据库、广告数据库的建设及广告数据的更新模式. 相似文献
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《International Journal of Digital Earth》2013,6(1):80-87
Abstract Cultures throughout the world are associating with the rivers. People depend upon the rivers and their tributaries for food, water, transport, and many other aspects of their daily lives. Unfortunately, human beings have not calculated the accurate lengths for the great rivers even today. The lengths of the rivers are very different in popular textbooks, magazines, atlases and encyclopedias, etc. To accurately determine the lengths of the principal rivers of the world, the combination of satellite image analysis and field investigations to the source regions is proposed in this paper. The lengths of the Nile, Amazon, Yangtze, Mississippi, Yellow, Ob, Yenisey, Amur, Congo and Mekong, with lengths over or close to 5000 km, were calculated using the proposed method. The results may represent the most reliable and accurate lengths of the principal rivers of the world that are currently achievable. 相似文献
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软科学这一术语是70年代在国外提出的.然而30多年以来,它在国外不仅未得到普遍的承认,而且对软科学的定义也还未能达成大体上一致的共识.而在改革开放后的中国,出于决策科学化和民主化的需要,经过一些领导人的提倡和支持,特别是通过1986年召开的软科学座谈会及1994年召开的全国软科学工作会议,软科学事业得到了蓬勃的发展.据初步统计,截止1998年底全国共有软科学研究机构1224个,研究人员32655人,初步形成了一支较为强大的研究队伍,并取得了数百项覆盖多个领域的研究成果,为支持各级各类的决策发挥了一定的作用. 相似文献
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Tobias Nilsson Benedikt Soja Kyriakos Balidakis Maria Karbon Robert Heinkelmann Zhiguo Deng Harald Schuh 《Journal of Geodesy》2017,91(7):857-866
The very long baseline interferometry (VLBI) Intensive sessions are typically 1-h and single-baseline VLBI sessions, specifically designed to yield low-latency estimates of UT1-UTC. In this work, we investigate what accuracy is obtained from these sessions and how it can be improved. In particular, we study the modeling of the troposphere in the data analysis. The impact of including external information on the zenith wet delays (ZWD) and tropospheric gradients from GPS or numerical weather prediction models is studied. Additionally, we test estimating tropospheric gradients in the data analysis, which is normally not done. To evaluate the results, we compared the UT1-UTC values from the Intensives to those from simultaneous 24-h VLBI session. Furthermore, we calculated length of day (LOD) estimates using the UT1-UTC values from consecutive Intensives and compared these to the LOD estimated by GPS. We find that there is not much benefit in using external ZWD; however, including external information on the gradients improves the agreement with the reference data. If gradients are estimated in the data analysis, and appropriate constraints are applied, the WRMS difference w.r.t. UT1-UTC from 24-h sessions is reduced by 5% and the WRMS difference w.r.t. the LOD from GPS by up to 12%. The best agreement between Intensives and the reference time series is obtained when using both external gradients from GPS and additionally estimating gradients in the data analysis. 相似文献
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In this letter, we are trying to resolve the electromagnetic problem for the movements of the superconducting particles of the protoplanetary cloud in the magnetic field of Saturn. The force of levitation (Meissner-Ochsenfeld phenomenon) is introduced to the field of planetary science for the first time. It is shown from our theoretical analysis that rings of Saturn might have a superconducting origin, and rings might levitate within magnetic equator plane of the planet. 相似文献
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根据残差二次型次小与最小之差进行整周模糊度确认的关键是差值的分布,只有得到了合理的差值分布才可确定合理的界值.文中基于原有的两种方法及这两种方法的不足,从理论上导出了满足条件的差值分布,并作了一定的说明. 相似文献