共查询到20条相似文献，搜索用时 62 毫秒
1.
论GPS精密工程测量技术设计的优选 总被引：2，自引：0，他引：2
论ＧＰＳ精密工程测量技术设计的优选于来法引言ＧＰＳ定位技术在工程测量中的应用愈来愈广泛，尤其在精密工程测量中的应用更是如此。例如欧洲核子研究中心大型对撞机的ＧＰＳ控制测量、美国斯坦福直线加速器ＧＰＳ控制网、加拿大太平洋铁路麦克唐纳德山隧道（１４．５ｋ... 相似文献
2.
在辽宁阜新引水工程中建立了ＧＰＳ三维控制网，从理论和实践的结合上对布网方案，数据处理、平差计算和成果精度作了分析；并重点研究了低丘山区应用ＧＰＳ进行水准测量的可能性。实践表明，在低丘山区运用ＧＰＳ水准测量，可以达到四等水准测量精度。最后对ＧＰＳ定位技术在水利、输油管线、输电线路、铁路高速公路等线性工程带状网测量中的应用提出几点看法。 相似文献
3.
平坦与丘岭地区GPS工程水准的研究 总被引：1，自引：0，他引：1
对ＧＰＳ工程水准网的布设、拟合法的模型选择和数据处理进行了探讨。通过实验网的布设和计算发现：在平坦和丘岭地区，控制面积不超出１００ｋｍ＾２时，按三等以上水准测量的精度联测网中６￣８个点，采用最佳三点平面拟合、二次多项式曲面拟合和ｈａｒｄｙ曲面拟合，求得ＧＰＳ工程水准高程的精度可达２￣４ｃｍ。 相似文献
4.
论城市ＧＰＳ测量网的精度北京市测绘设计研究院孟庆遇我国自１９８６年引进先进的ＧＰＳ技术以来，应用ＧＰＳ技术进行城中控制网的改建、扩建、重建工作越来越普遍。到目前，全国已有几十个大、中、小城市采用ＧＰＳ技术布设城市控制网和工程控制网，仅“全国城市测量Ｇ... 相似文献
5.
在推导短距离ＧＰＳ测相双差观测方程的近似表达式的基础上,分析了卫星几何状态与基线位置对短基线解精度的影响,结合北京地铁复八线ＧＰＳ控制网资料分析,提出了工程及城市控制网型设计原则。 相似文献
6.
至今，国内还很少应用ＧＰＳ技术进行隧道控制测量，有关隧道ＧＰＳ控制网的计算还没有形成一套完整，系统的方法，本文介绍采用投影约束法计算ＧＰＳ网施工坐标，讨论了贯通误差的预计方法，并在一座长８．２ｋｍ，现已贯通的隧道控制网上进行工程验证，最后还提供了ＧＰＳ控制网的施工复测建议。 相似文献
7.
讨论ＧＰＳ网的平面坐标和高程位置的转换问题，介绍适用于工程测量应用的简单实用的平面坐标转换模型，还阐述了ＧＰＳ网高程系统变换的方法，最后介绍美国ＤＭＡ的应用实例。 相似文献
8.
讨论了机场工程测量中的几个问题,如机场坐标系、ＧＰＳ机场控制网的建立、机场数字测图及施工放样等,并提出实际工作应采取的措施。 相似文献
9.
本文论述了按地面同坐标和协方差参考系中的位置基准和方位基准作ＧＰＳ网平差和转换的各种方法，在采用ＧＰＳ定位技术检测和改善原有城市或工程控制网时，宜根据不同情况而选择采用。 相似文献
10.
11.
国际重力卫星研究进展和我国将来卫星重力测量计划 总被引：12，自引：3，他引：9
本文首先分别介绍了国际已经成功发射的专用地球重力测量卫星CHAMP、GRACE以及即将发射的GOCE、GRACE Follow-On和专用月球重力探测卫星GRAIL的研制机构、轨道参数、关键载荷、跟踪模式、测量原理、科学目标和技术特征;其次,阐述了当前相关学科对地球重力场测量精度的需求;最后,建议我国在将来实施的卫星重力测量计划中首选卫星跟踪卫星高低\低低模式,尽快开展轨道参数优化选取的定量系统研究论证和重力卫星系统的误差分析,依据匹配精度指标先期开展重力卫星各关键载荷的研制以及尽早启动卫星重力测量系统的虚拟仿真研究。 相似文献
12.
Applied Research Laboratories, The University of Texas at Austin (ARL:UT) has established a cross platform open source software
project called the GPSTk or the GPS Toolkit. The GPSTk consists of a library and collection of applications that support GPS
research, analysis, and development. The code is released under the terms of the Lesser GNU Public License. The GPSTk supports
a broad range of functionality. This includes reading and writing observations in standard formats, such as RINEX, BINEX,
and SP3, ephemeris evaluation, position determination, receiver autonomous integrity monitoring (RAIM), atmospheric delay
modeling, cycle slip detection and correction, and P-code generation. The GPSTk provides the core set of functionality that
is used for GPS research and development at ARL:UT. ARL:UT has been involved with satellite navigation since Transit (the
precursor to GPS) in the 1960s and is currently conducting research in a wide variety of GPS-related fields, including precise
surveys, monitor station networks, and ionospheric studies. The GPSTk is a community-wide resource for all users of GPS and
GNSS technology. Participation is welcomed in all areas including: bug reports, new algorithms, suggestions for improvement,
and contributions of additional functionality or applications. ARL:UT continually improves the library, shepherds community
participation, and is committed to the project’s development and maintenance.
The GPS Toolbox is a column dedicated to highlighting algorithms and source code utilized by GPS Engineers and scientists.
If you have an interesting program or software package you would like to share with our readers, please pass it along; e-mail
it to us at gps-toolbox@ngs.noaa.gov. To comment on any of the source code discussed here, or to download source code, visit
our website at . This column is edited by Stephen Hilla, National Geodetic Survey, NOAA, Silver Spring, Maryland, and Mike Craymer, Geodetic
Survey Division, Natural Resources Canada, Ottawa, Ontario, Canada. 相似文献
13.
SVG是一种基于XML的用来描述二维矢量图形和矢量/栅格混合图形的标记语言,虽然SVG不是为了面向地理空间数据发布而制定的标准,但它的许多特性都能被广泛地应用到WebGIS中,从而实现矢量WebGIS。由于SVG通过简单的文本语句描述矢量图像,所以SVG通常数据量很小,并且SVG支持GZIP压缩,所以基于SVG构建WebGIS能减轻网络传输负载,加快地图显示速度。SVG内置了对JavaScript的支持,且SVG可通过DOM解析映像成内存中的树型结构,所以客户层可通过JavaScript对DOM的操作实现对地图的缩放、漫游、查询、图层控制等交互操作。 相似文献
14.
Jagannathan Krishnamurthy Arul Mani Venkatakrishnan Jayaraman M Manivel 《International Journal of Applied Earth Observation and Geoinformation》2000,2(3-4)
To demonstrate the capabilities of remote sensing and Geographic Information System (GIS) techniques for groundwater resources development in hard rock terrains, specifically for the demarcation of suitable sites for artificial recharge of groundwater aquifers, a study was carried out in the Kallar Basin, which is located in parts of the Salem and Tiruchirapalli districts, Tamil Nadu, India. Thematic maps defining lithology, lineaments, landforms, landuse, drainage density, thickness of weathered zone, thickness of fractured zone, hydrological soils, and well yield were prepared from data collected by the Indian Remote Sensing Satellite (IRS) -1C and by conventional methods. All the thematic layers were integrated using a GIS-based model developed specifically for this purpose, enabling a map showing artificial recharge zones to be generated. The exact type of artificial recharge structure, eg, check dam, nallabund, gully plugging and percolation pond, suitable for replenishing groundwater was identified by superposing a drainage network map over an artificial recharge zones map. The GIS-based demarcation of artificial zones developed in the study was based on logical conditions and reasoning, so that the same techniques (with appropriate modifications) could be adopted elsewhere, especially in hard rock terrain, where the occurrence of groundwater is restricted and subject to greater complexity. 相似文献
15.
MURUGESAN Vasanthavigar KRISHNARAJ Srinivasamoorthy KANNUSAMY Vijayaragavan SELVARAJ Gopinath SUBRAMANYA Sarma 《地球空间信息科学学报》2011,14(1):17-26
The main objective of the study is to identify groundwater potential zones in Thirumanimuttar basin with an integrated approach using Remote Sensing and geographical information system(GIS).FCC Image of Landsat TM 30 m resolution data and topographic maps has been used to generate thematic maps like geology,geomorphology,lineament and lineament density,drain-age,drainage density,and slope map of the study area.A number of geomorphic units such as Denudational hills,structural hills,Bajadas,Colluvial plain,Pediplain,Deep Pediment and Alluvial plains have been observed.A composite groundwater potential map has been generated as very high,high,medium,low and very low based on the groundwater availability area.The upper,mid-dle and downstream of the basins have been identified as potential zones for groundwater exploration.The regions of lineaments and intersecting lineaments proved for groundwater potential zones.The data generated was validated with field checks and ob-served to be in conformity with the same. 相似文献
16.
大气气溶胶成分的复杂变化导致其在气候变化评估中具有很高的不确定性。气溶胶成分遥感利用遥感观测的气溶胶光学—微物理参数,定量估计整层大气气溶胶主要成分含量,具有实时快速、空间覆盖、保持气溶胶自然状态等特点。本文介绍了近年来气溶胶成分遥感在理论基础和观测研究方面的进展情况。首先,在简要回顾反演算法发展的基础上,以目前较先进的成分遥感分类模型(包括黑碳、棕色碳、沙尘、非吸光有机物、细粒子无机盐、海盐和水)为例,详细分析了气溶胶成分遥感反演的思路。据此提出了基于气溶胶综合光学—微物理特性(包括光学吸收/散射、粒径尺度、形状等敏感性特征参数)的气溶胶成分遥感识别方法。之后,结合气溶胶混合方式,讨论了复折射指数计算方法及其对成分反演的影响,并给出了利用同步化学采样观测验证气溶胶成分遥感的一些结果示例。最后,结合观测手段拓展、成分模型优化、反演精度提升、应用能力推广等4个方向,展望了大气气溶胶成分遥感的发展趋势,及其在全球气候变化评估等领域的应用。 相似文献
17.
In the period after the First World War the Ordnance Survey was relatively slow to recognise the contribution that air survey could make to its work. In part, this was due to external constraints on budgets, which helped to stifle innovation. However, the views of the four Directors General, Close, Jack, Winterbotham and MacLeod, were to play large roles in determining the energy with which innovations were adopted. Both Close and Winterbotham were generally sceptical about the value of air survey, while Jack was well disposed, but constrained by budget limitations. In MacLeod, however, air survey was to find a convinced champion. This paper explores the roles played by the key players and how, in the late 1930s, significant advances were made. 相似文献
18.
19.