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从GPS网布设的不同网形结构，通过平差计算结果，对点位精度的影响进行了探讨，得出在不同的情况下，如何布设GPS网网形的结论。 相似文献
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对GPS网采用全面边连式结构、点连式结构和导线网等三种不同网形进行平差分析,得出结果是：全面边连式GPS网形结构强,点位精度高,适用于高精度工程控制网。点连式GPS网网形结构的点位精度与全面边连式网的精度相当,但点连式GPS网可大大减少野外观测和计算工作量。在满足精度要求的情况下,优化GPS网的网形设计,可减少工作量,大大提高生产效率。 相似文献
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基于GPS静态相对测量,基线数据处理采用双差观测值单基线解算的一般模式,讨论GPS网基线解算和3维无约束平差的公式,得出GPS网的质量与基线向量质量和GPS网结构有关,而与网形和点位无关,并通过实验数据,分析验证了这一观点,提出了一些有益的结论。 相似文献
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将三维激光扫描技术与GPS技术融合可解决点云数据实时定位问题,但制约该技术推广应用的是其精度是否满足工程需求。为了检验、评价三维激光扫描仪与差分GPS结合的测量精度,需要建立一个合适范围的基准网,基准网内有足够的已知点与融合GPS数据的三维激光扫描点云整体精度进行比较,分析该方法测量的误差大小与误差性质,从而确定该技术的适用性。本文以Reigl VZ-1000三维激光扫描仪为例,主要研究小区域基准网构建、测量以及数据的平差处理,依据《工程测量规范》、《城市测量规范》等,通过踏勘选点、构网、网形设计、外业测量,建立小区域基准网,并利用PA2002软件进行了高程闭合环和闭合导线网的平差,从而获得了符合要求的基准网。 相似文献
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针对GNSS三维无约束平差不依赖基准且拥有高精度几何网形的特点,以GNSS监测网作为一个整体的时空观测单元,由GNSS网测站间相互关联的所有基线长度和基线夹角变化综合衡量网形的变化,用网形的变化集中反映区域地壳形变信息。利用地壳形变高空间相关性的特点,采用主成分时空响应分析的方法实现了区域地壳形变信息的快速提取。通过对2013年芦山Ms7.0地震近场区域陆态网GPS基准站2010—2014年观测数据的解算,提取并分析了对应地震前后近场区域地壳形变时空分布特征及形变的动态演变过程。 相似文献
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本文通过对江阴市Ｄ、Ｅ（东部）级ＧＰＳ网和溧阳市Ｅ级ＧＰＳ网,选取不同的观测基线向量,以构成不同的网形,分别进行无约束平差,比较分析各种网形的平差结果,从而得出较为经济、成果可靠、精度良好的ＧＰＳ网形,来指导生产实践。 相似文献
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基线是GPS测量网解算中的基本量，解算过程中占有重要位置。本文介绍了GPS测量中基线的选取方法，研究了GPS网中独立基线的选取对解算结果的影响。 相似文献
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GPS网精度影响因素研究 总被引：1，自引：1，他引：0
鉴于GPS控制网在各类工程中的广泛应用,本文结合实例针对各因素对GPS网平面精度的影响进行了探讨和研究,最后指出在满足精度要求条件下如何考虑各影响因素从而达到降低作业成本的目的。 相似文献
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针对已分割出的建筑物立面,提出了以基尼系数作为损毁指数对倾斜航空影像中建筑物立面损毁检测的方法。该方法首先通过改进的k-means算法分割出建筑物立面的门窗和墙面,然后利用Canny算法对分割影像进行边缘检测提取统计特征,最后利用经济学中的基尼系数来判断建筑物立面是否损毁。实验结果表明,本文方法在没有先验信息的情况下仅利用单时相倾斜航空影像就能简单高效地判定建筑物立面损毁。 相似文献
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Ze Tang Haifeng Zheng Zhibin Ren Dan Zhang Peijiang Wang Chang Zhai Mingxing Cui Xingyuan He 《Journal of the Indian Society of Remote Sensing》2018,46(2):287-296
The urban forest plays an important role in mitigating the urban heat island. However, the cooling effects of different types of urban forest are unclear. In addition, the fairness of the cooling effect of the urban forest has not been discussed. In this study, the land surface temperature (LST) of Changchun City, China was obtained from Landsat ETM+ data and then correlated with detailed urban forest information derived from the high-spatial-resolution Google Maps in order to determine the cooling intensity and cooling distance of different types of urban forest. In addition, the Gini coefficient was used to evaluate the equity of cooling services provided by the urban forest. The results indicated that (1) the total area of urban forest in Changchun City is 106.69 km2 and is composed of attached forest (AF, 45.83 km2), road forest (RF, 23.87 km2), ecological public welfare forest (EF, 23.24 km2) and landscape forest (LF, 13.75 km2); (2) the cooling effect of different types of urban forest varies. The cooling intensity and cooling distance are 3.2 °C and 125 m (LF), 0.2 °C and 150 m (EF) and 0.6 °C and 5 m (AF), and RF had no cooling effect; and (3) the cooling effect of urban forest benefits approximately 760,000 people in Changchun City, and the Gini coefficient of the cooling services of urban forest was 0.29, indicating that the cooling service was reasonable. Therefore, we demonstrated that ETM+ and Google data are a convenient and affordable approach to study the LST on an urban scale, and the Gini coefficient could be a meaningful indicator to evaluate urban ecological services. 相似文献
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This paper summarizes a few spatial statistical analysis methods for to measuring spatial autocorrelation and spatial association, discusses the criteria for the identification of spatial association by the use of global Moran Coefficient, Local Moran and Local Geary. Furthermore, a user-friendly statistical module, combining spatial statistical analysis methods with GIS visual techniques, is developed in Arcview using Avenue. An example is also given to show the usefulness of this module in identifying, and quantifying the underlying spatial association patterns between economic units. 相似文献
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Application of integration of spatial statistical analysis with GIS to regional economic analysis 总被引：2，自引：0，他引：2
CHENFei DUDaosheng 《地球空间信息科学学报》2004,7(4):262-267
This paper summarizes a few spatial statistical analysis methods for to measuring spatial autocorrelation and spatial association, discusses the criteria for the identification of spatial association by the use of global Moran Coefficient, Local Moran and Local Geary. Furthermore, a user-friendly statistical module, combining spatial statistical analysis methods with GIS visual techniques, is developed in Arcview using Avenue. An example is also given to show the usefulness of this module in identifying and quantifying the underlying spatial association patterns between economic units. 相似文献
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老挝是一个发展中国家,境内的大多数地方没有开展过土地利用/土地覆盖调查。本文选择老挝琅勃拉邦省的Phonxay区为研究区域,利用Landsat OLI数据进行土地利用/土地覆盖遥感调查与分析。研究过程中,利用ArcGIS Desktop选择训练样本和验证样本,通过Python和ArcPy编程开发了图像分类、精度评价以及面积统计的工作流程序,实现了快速得到分类结果和精度评价信息,分类结果的总精度为89.53%,Kappa系数为0.81。 相似文献
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为了实现地物精准分类,需要有效地提取与分析高光谱遥感图像中丰富的空—谱信息。提出一种适用于高光谱遥感图像分类的变异系数与卷积神经网络相结合(CV-CNN)的方法。这种新方法引入变异系数的思想来衡量高光谱遥感图像不同波段之间的相似性和差异性,从而提出类间变异系数(CVIE)和类内变异系数(CVIA)的概念。通过计算(CVIE)~2/CVIA的值来剔除高光谱遥感图像中的低效波段,然后提取每个像素的空一谱信息,并对其进行2维矩阵化操作,转化为便于卷积神经网络(CNN)输入的灰度图像,最后采用自行构建的适合于高光谱遥感图像分类的CNN模型进行分类。Indian Pines和Pavia University两组数据的实验结果表明,该方法在两种数据集下的总体精度分别达到98.69%和99.66%,有效地改善了高光谱遥感图像的分类精度。 相似文献
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Daniel A. Griffith 《Journal of Geographical Systems》2000,2(2):141-156
The Moran Coefficient spatial autocorrelation index can be decomposed into orthogonal map pattern components. This decomposition
relates it directly to standard linear regression, in which corresponding eigenvectors can be used as predictors. This paper
reports comparative results between these linear regressions and their auto-Gaussian counterparts for the following georeferenced
data sets: Columbus (Ohio) crime, Ottawa-Hull median family income, Toronto population density, southwest Ohio unemployment,
Syracuse pediatric lead poisoning, and Glasgow standard mortality rates, and a small remotely sensed image of the High Peak
district. This methodology is extended to auto-logistic and auto-Poisson situations, with selected data analyses including
percentage of urban population across Puerto Rico, and the frequency of SIDs cases across North Carolina. These data analytic
results suggest that this approach to georeferenced data analysis offers considerable promise.
Received: 18 February 1999/Accepted: 17 September 1999 相似文献
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Tropical deforestation through logging activities poses a direct threat to biodiversity. However, the detection of logging has remained a challenge. Based on study sites in Zimbabwe and Zambia, we tested whether the Normalized Difference Vegetation Index (NDVI) and the Coefficient of Variation in NDVI (CVNDVI) derived from high and medium spatial resolution satellite data could be used to detect logging in dry and wet miombo woodlands. Separately, we integrated NDVI and CVNDVI in logistic regression to test whether each can be used to successfully predict logging in the study sites. We tested whether the spatial resolution of satellite data has an effect in detection of logging using NDVI and CVNDVI derived from Landsat 8 and Worldview-2. Based on the ROC curves, we concluded that remotely sensed data could provide an effective predictive tool for detecting logging. However, in wet miombo woodlands the predictive power of remotely sensed data is weak. 相似文献