共查询到19条相似文献，搜索用时 234 毫秒
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基于特征点的高程点自动抽稀法 总被引：1，自引：0，他引：1
针对传统地形图缩编中高程点抽稀存在的问题,提出基于特征点的高程点抽稀的方法,使用此方法一方面可以保留特征点处的高程点,另外可以实现高程点的自动抽稀。 相似文献
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为进一步提升复杂地形条件下无人机激光雷达(Light Detection and Ranging,LiDAR)点云数据构建数字高程模型的效率与精度,以2022年北京冬奥会延庆赛区场馆建设用地为实验区,按照不同抽稀比例,对实验区原始无人机激光雷达点云中分类出的地面点数据进行抽稀处理,利用克里金插值算法对不同密度地面点数据进行插值处理,结合高程中误差、平均绝对误差对生成的数字高程模型进行双重精度评定,得出以下结论:对于复杂地形而言,随着点云数据密度的下降,数字高程模型建模效率明显提升,但地形特征逐渐模糊,数据精度级别逐级降低,其中高程中误差由0.381 m增大至1.914 m,平均绝对误差值由0.335 m增大至1.357 m.在满足精度要求的前提下,对LiDAR点云数据进行适度抽稀处理,可保障生产成本与时效. 相似文献
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为解决高程点与等高线高程矛盾,对高程点与等高线的空间关系进行了分析,参考测绘成果质检常用方法,提出了2种高程不一致检测算法;并结合FME编程特点,融合2种算法的优点,快速实现编程。该检测程序简单高效、包容性强。 相似文献
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本文以观音机场ＧＰＳ定位测量数据并结合水准测量数据，探讨ＧＰＳ点的水准高程计算方法，采用曲面拟合法和强制符合法等不同的处理方法由已知的公共点的水准高程推求其余ＧＰＳ点的水准高程。计算结果表明，对于局部平坦地区，高程异常变化有规律时，采用曲面拟合能够满意的结果。如果采用强制符合法，必须把已知公共点的水准高程加上高程异常值，否则直接已知公共点的水准高程进行强制符合平差，会使结果产生较大误差，一般，由于 相似文献
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就GPS高程转换进行研究,论述了GPS高程转换的过程及常用方法,特别对数学模型拟合法进行了讨论,最后通过对某地区GPS拟合高程与水准高程的精度对比分析,提出了利用GPS观测值加已知高程点拟合求待定点高程的方法,论述了等级网GPS拟合高程可以达到的普通几何水准测量精度。 相似文献
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山区全站仪三角高程与GPS拟和高程比较精度之分析 总被引：1，自引：0，他引：1
通过在山区测量中,全站仪三角高程与GPS拟和高程的比较,可得出小面积山区航测成图项目外业像控点高程测量可用GPS拟和高程替代全站仪三角高程作业方法的结论。 相似文献
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利用GPS点水准联测数据,通过曲面拟合的方法得到高程异常值;最后通过对GPS拟合高程与水准测量高程的精度对比分析,论述了等级网GPS高程拟合在矿区地表变形监测中的可行性。 相似文献
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GPS水准高程拟合精度的探讨 总被引：2，自引：0，他引：2
本文根据ＧＰＳ定位技术,在四等ＧＰＳ控制网测量中作了ＧＰＳ水准高程试验,对高程拟合起算点的数量,精度,位置以及整体和分区拟合所获得的各种拟合精度进行了分析和探讨,得出了有益的结论。 相似文献
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DTM法土方量计算是工程施工中较为常用的一种方法,选取不同的高程点将获得不同的DTM,进而会影响到工区内土方量计算的精度。本文对不同工区的多种高程点选取方式进行了实验及分析,从中总结了一种较为有效的并兼顾精度的工区边缘高程点选取方法。 相似文献
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A review of Soviet research describes methods of combining remote sensing and geodetic data in cartometric data bases—for the purposes of compiling more detailed and accurate “three-dimensional” terrain maps. The major objective is to provide, by means of photogrammetric techniques employing stereopairs or series of overlapping images, elevational data on selective key geomorphological points (along structure lines, summits of ridges, valley bottoms, etc.) which can be used to supplement (or replace) data obtained for the control points of a rectangular grid. Creation of digital models from these “geomorphological” points provides more accurate three-dimensional terrain maps. Translated from: Vestnik Moskovskogo Universiteta, geografiya, 1986, No. 6, pp. 56-64. 相似文献
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The authors describe a procedure for the compilation of maps of the avalanche hazard in high-mountain regions of Afghanistan. The basic sources of information include space imagery (photographs and scanner imagery), weather station data, and other geographic information on relief, elevation, location of moisture sources, etc. The methodology features the compilation of series of increasingly more specific and informative maps and graphs regarding the avalanche hazard: terrain types, snow cover depth and seasonal extent, duration of snow cover and its elevational zonation, snow as a factor in avalanche formation, and summary map of avalanche hazard. Translated by Elliott B. Urdang, Providence, RI 02906 from: Materialy glyatsiologicheskikh issledovaniy, 1991, No. 71, pp. 86–93. 相似文献
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A variety of DEM products are available to the public at no cost, though all are characterized by trade-offs in spatial coverage, data resolution, and quality. The absence of a high-resolution, high-quality, well-described and vetted, free, global consensus product was the impetus for the creation of a new DEM product described here, ‘EarthEnv-DEM90’. This new DEM is a compilation dataset constructed via rigorous techniques by which ASTER GDEM2 and CGIAR-CSI v4.1 products were fused into a quality-enhanced, consistent grid of elevation estimates that spans ∼91% of the globe. EarthEnv-DEM90 was assembled using methods for seamlessly merging input datasets, thoroughly filling voids, and smoothing data irregularities (e.g. those caused by DEM noise) from the approximated surface. The result is a DEM product in which elevational artifacts are strongly mitigated from the input data fusion zone, substantial voids are filled in the northern-most regions of the globe, and the entire DEM exhibits reduced terrain noise. As important as the final product is a well defined methodology, along with new processing techniques and careful attention to final outputs, that extends the value and usability of the work beyond just this single product. Finally, we outline EarthEnv-DEM90 acquisition instructions and metadata availability, so that researchers can obtain this high-resolution, high-quality, nearly-global new DEM product for the study of wide-ranging global phenomena. 相似文献
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G. Singh M. S. Sarkar A. Pandey S. Lingwal I. D. Rai B. S. Adhikari G. S. Rawat R. S. Rawal 《Journal of the Indian Society of Remote Sensing》2018,46(10):1625-1635
Effective quantification of land cover changes remains a challenge in Himalayan hills and mountains, and has a colossal value addition for natural resource management. Here we present a new robust method for classifying land cover vegetation at physiognomic scale along steep elevational gradients from ~?200 to ~?7000 masl in the Kailash Sacred Landscape, Western Himalaya, India along with four decades of land use and land cover changes (1976–2011) using remote sensing techniques coupled with intensive ground surveys. Results show that forest cover loss was minimum ca 7.14% of existing forest in 1976; but, however forest fragmentation is high especially in montane broad-leaved and subtropical needle leaved forests. This change largely impacted the quality of valuable tree species such as Quercus spp. Post 1976, continuous migration forced conversion of high altitude agricultural lands into grasslands and scrublands. Human settlement expansion was high especially in low altitudinal range valleys between 1000 and 2000 masl and has increased 6.76 fold since 1976, leading to high forest fragmentation in spite of reduced agriculture area in the landscape. Our physiognomic level classified land cover map will be a key for forest managers to prioritize conservation zones for protecting this unique forest land. 相似文献
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Christopher Potter Peggy Gross Vanessa Genovese Marie-Louise Smith 《Carbon balance and management》2007,2(1):1-11