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为了解决过去土地详查、变更调查由于采用图纸调查,图件管理,调查技术和手段落后,基础资料难以做到图件、数据、实地相一致,不能准确地反映土地利用现状的问题,本文结合了"3S"技术在现阶段土地利用更新调查的应用,主要论述"3S"技术是现阶段土地利用更新调查中的最佳技术。首先介绍"3S"技术的优点和在土地利用更新调查中应用,然后根据新旧技术的比较分析了县级土地利用更新调查具体方法,探讨了3S集成技术在土地利用更新调查中的应用环境。论文研究结果表明:应用"3S"技术是目前土地利用更新调查的最佳途径。 相似文献
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自1996年开始每年一次的国家土地变更调查,基本上采取传统的测量工具和手段,效率低下,误差较大,加之近10年来土地利用现状的剧烈变化,已越来越难以保证国土资源管理对现势性好、精度高的土地利用现状数据的需要。近年来快速发展的全球定位、遥感、地理信息系统等技术,虽然已不同程度地应用于土地变更调查,但国内目前缺乏基于3S技术集成的面向土地变更调查的专用软件,未能改变各单位因使用软件标准不同,造成的土地统计数据成果不统一、作业效率低等弊端。基于3S技术集成的现代化土地变更调查技术,长期以来成为业内攻关的重点。 相似文献
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土地资源调查中3S集成应用的关键技术 总被引:10,自引:0,他引:10
针对土地资源管理中对现势性土地利用信息的需求,结合遥感、GIS和GPS技术特点及其发展现状,阐述将3S技术集成应用于土地利用调查信息采集、处理,以及土地利用基础数据快速更新中的关键技术,并对未来这一技术领域的发展趋势进行展望。 相似文献
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贵州省作为我国西南地区重要的粮食产量基地,其耕地保护尤为重要。目前贵州省仅存51块万亩以上耕地大坝,掌握其土地利用现状数据是耕地保护的基础准备。近几年来伴随着无人机技术的高速发展及广泛应用,土地利用现状调查手段有了新的变化。针对西南地区山地、平台地,多云多雾的天气条件,常规卫星影像获取能力受限,运用无人机航空影像进行土地现状调查具有很大优势。本文根据实际参与的基于无人机数据进行贵州省万亩大坝土地利用现状调查项目,从实践角度探索运用高分辨率影像进行土地调查技术方法,希望这些技术方法能为行业后续此类应用提供参考思路。 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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跟踪世界发展动态 致力地球重力场研究 总被引:12,自引:6,他引:12
宁津生 《武汉大学学报(信息科学版)》2001,26(6):471-475
比较系统、扼要地叙述了笔者所在单位40余年来坚持跟踪世界发展动态,致力于地球重力场理论和方法的研究,并从教学和生产需要出发,在地球重力场研究方面所获得的一些有理论意义和实用价值的成果。 相似文献