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DLG数据转换为GIS入库数据,不仅是图形数据格式的转换,还包括属性数据的挂接。针对目前已有DLG数据的特点,本文提出数据入库的方法及转换软件的选择,确保入库数据的质量可满足空间分析、管理、规划和决策的需求。 相似文献
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李颖 《测绘与空间地理信息》2017,(2):167-168
以制作辽宁省1∶10 000 DLG数据为例,简要地陈述了采用EPS制作DLG数据的基本方法,总结了利用EPS制作DLG数据的特点,较全面地阐述了EPS制作DLG数据从制作原理到编辑、入库完成图库一体化的全过程。通过实践应用,EPS系统有效克服了传统制图工艺的缺陷,能够快速、高效地完成辽宁省1∶10 000 DLG数据制作,大大提高了生产效率和质量。 相似文献
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以《江苏省1∶500 1∶1 000 1∶2 000基础地理信息地形要素数据规范》为基础,制定了MDIGS数据向GIS数据的转换方案,通过Arc GISEngine和Teigha.net开发数据无损转换工具,实现了MDIGS平台DLG数据向ESRI平台Geo Database数据库自动、高效入库。 相似文献
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城市基础测绘成果是构建空间地理信息数据库的重要数据来源。结合增城市航摄成图数据入库工作,详细阐述了基于CAD结构的DLG数据入库过程,实现由地形图库数据到空间地理信息数据的转换。 相似文献
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2010年1∶1万DLG入库数据涉及9个测区共计1 852幅,由于生产这些数据时标准不一致,造成数据间的差异,给数据入库带来一定的困难。为了满足入库数据标准,探索通过软件工具与测区数据处理方案相结合的方法来处理入库数据不一致的数据现状,以确保入库数据的一致性和可靠性。 相似文献
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不同时期、不同测区的1：10000 DLG数据,由于执行不同的生产标准,因此造成数据间的差异,并给数据入库带来巨大的困难。为满足入库数据标准,探索通过软件工具与测区数据处理方案相结合的方法来处理入库数据不一致的数据现状,以确保入库数据的一致性和可靠性,并介绍该处理方法的相关技术。 相似文献
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本文介绍了在浙江省1：5万DLG更新过程中对数据的处理和检查以及数据转换的一些过程和方法，阐述了生产符合国家1：5万地形数据库更新要求的地理信息数据的过程。 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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本文从理论上推导了工程摄影测量中交向摄影方式各元素影响物点坐标精度的严密公式,并根据理论分析的结果,采用先进的数码相机和量测相机进行了一定的试验,在仔细分析试验结果的基础上,找出了工程摄影测量中交向摄影最佳的交向角、摄影基线、摄影距离和摄影比例尺等参数,对物点坐标总精度的影响规律。实际作业中,要使最佳交向摄影方式获得最理想的点位精度,所总结出的结论是可行的。 相似文献