共查询到20条相似文献,搜索用时 453 毫秒
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针对城市管线数据重复探测,综合管线数据生产成本高的问题,该文提出一种几何相似度与空间场景结构相似度相结合的管线数据多步骤匹配算法。以路划(stroke)作为匹配单元,使用长度、角度和空间距离指标通过分配不同的权重和阈值来计算几何相似度,将几何特征与邻域空间的空间拓扑关系相结合计算空间场景结构相似度。设计基于弧段分解的stroke部分匹配算法最大限度地保留了原有的两组地下管线数据。设计基于顶点分解的stroke部分匹配算法可以解决单线间局部匹配中的问题(如生长、缩短、拓扑变化等)。实验结果表明,该文所提算法具有较高的匹配精度、召回率和运行效率,研究结果可以有效降低综合管线数据的生产成本,提高专业管线数据质量。 相似文献
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近年卫星重力测量技术和各种重力模型得到不断发展,使得利用重力场模型进行GPS点高程转换的精度和可靠性都获得了极大提升。利用SRTM、DTM2006.0模型和EGM2008模型求得工作区域GPS点剩余高程异常,并进行残余高程异常拟合,建立江西省新余市某工程的剩余高程异常转换计算方法。通过对点的高程数据比较,说明此方法可以提高工作区域GPS高程转换的精度。 相似文献
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《测绘文摘》1999,(2)
CH991061 三维显示中的DTM数据简化算法/刘玮(郑州测绘学院)…∥解放军测绘学院学报。—1999,16(1)。—40~43 提出了一种将图形生成技术和图像处理技术相结合的DTM数据简化算法。依据一定的分辨率条件,将DTM数据转化到二维图像空间,此时DTM数据的冗余就表现为具有某种一致性的区域,利用图像处理技术找到区域轮廓并将其轮廓线用多边形在满足一定的误差要求下逼近,从而得到DTM在二维空间的特征点,然后将这些二维空间的特征点利用Delaunay部分三角化,再映射到三维空间,这样,在简化数据的同时,得到一个满足保真要求的TIN模型。实验数据采用1024×1024的DTM,在误差小于5%时得到6681个TIN三角形,结果证实了文中方法的有效性和可行性。图4参8(李慧典) 相似文献
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本通过阳泉露天矿实际验收测量中收集的数据,从外业测量、内业计算、量图几个方面进行分析,找出验收测量中影响采剥量不准确的主要因素,从而进一步提高验收测量的精度。使验收测量精度符合有色金属矿山生产技术规程的规定。 相似文献
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采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的
污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体
污染变化曲线,得出污染物浓度随着远离上游而增加。 相似文献
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Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data 总被引:5,自引:0,他引:5
C. Bhuiyan R.P. Singh F.N. Kogan 《International Journal of Applied Earth Observation and Geoinformation》2006,8(4):289-302
The hard-rock hilly Aravalli terrain of Rajasthan province of India suffers with frequent drought due to poor and delayed monsoon, abnormally high summer-temperature and insufficient water resources. In the present study, detailed analysis of meteorological and hydrological data of the Aravalli region has been carried out for the years 1984–2003. Standardised Precipitation Index (SPI) has been used to quantify the precipitation deficit. Standardised Water-Level Index (SWI) has been developed to assess ground-water recharge-deficit. Vegetative drought indices like Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) and Vegetation Health Index (VHI) have been computed using NDVI values obtained from Global Vegetation Index (GVI) and thermal channel data of NOAA AVHRR satellite. Detailed analyses of spatial and temporal drought dynamics during monsoon and non-monsoon seasons have been carried out through drought index maps generated in Geographic Information Systems (GIS) environment. Analysis and interpretation of these maps reveal that negative SPI anomalies not always correspond to drought. In the Aravalli region, aquifer-stress shifts its position time to time, and in certain pockets it is more frequent. In comparison to hydrological stress, vegetative stress in the Aravalli region is found to be slower to begin but quicker to withdraw. 相似文献
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Piyoosh Rautela Ramesh Chandra Lakhera 《International Journal of Applied Earth Observation and Geoinformation》2000,2(3-4)
The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies. 相似文献
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ZHAN F. Benjamin 《地球空间信息科学学报》2011,(1)
Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200... 相似文献
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GNSS系统及其技术的发展研究 总被引:3,自引:1,他引:2
阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议. 相似文献
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“4D”技术及其应用 总被引:13,自引:0,他引:13
介绍“4D”(即数字地面模型、数字正射影像、数字栅格地图和数字线划地图)系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。 相似文献
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《International Journal of Digital Earth》2013,6(1):66-87
Abstract Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised. 相似文献
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自动车辆定位导航系统中传感器的误差分析 总被引:1,自引:0,他引:1
对国界定位导航系统中几种常见的辅助传感器所产生的误差进行了分析,导出了不同传感器的误差模型。这些误差模型是估计车辆位置的扩展卡尔曼滤波器的基础,同时也为选择适当的传感器提供了理论根据。 相似文献