共查询到20条相似文献，搜索用时 15 毫秒
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L. N. Vasil'yev A. B. Kachalin V. M. Moralev Ye. N. Terekhov A. S. Tyuflin 《地理信息系统科学与遥感》2013,50(2):135-143
Analysis of data on the lineament network of the Kola Peninsula obtained through interpretation of space images at different scales provides an indication of the multifractality of lineament densities and the possibility of the geologic interpretation of the spectrum of fractal dimensions. The invariance of the distribution of densities of images of the lineament network at small and large scales reveals the scaling properties of these structural elements, and objectively reflects the heterogeneity of the geologic medium. 相似文献
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《测量评论》2013,45(84):252-264
AbstractIn view of the limitations of the use of plotting machines in air triangulation a detailed investigation of the practical possibilities of the analytical methods has become necessary, especially now that inexpensive means of reducing the labour of calculation is in course of realisation.In analytical methods it is practically possible to correct the measured photographic coordinates for determinable errors. Also, the use of a reseau as developed by the Ordnance Survey facilitates the reduction of several distortions. It is however argued and demonstrated that some errors of a local character remain without effective checking.A discussion of the nature of local errors shows that the number of points usually employed for relative setting is too small to be effective in disclosing them. An increase of the number of observed points is therefore suggested, and should be expected to improve the accuracy in the meanwhile.An assessment of the value of doubling the number of minor control points and of the improvement resulting from the use of reseau is made from a statistical analysis of data kindly provided by the Ordnance Survey.Comparison of 89 overlaps carrying one centimetre reseau and 100 overlaps without the reseau shows that the use of reseau reduced the root mean square error of evaluation of want of correspondence by 13 per cent., which just passes the 10 per cent. point of significance. The use of double minor control on the reseau overlaps gave an improvement which is about equal to that due to the use of the reseau. Doubling the number of minor control points is shown to increase the effective number of degrees of freedom from one to an average of four, which should reduce effectively the chances of large errors passing unnoticed through the stages of relative setting.Work on the frequency of local errors of various sources is in hand, and will probably be published in later issues of the Review. 相似文献
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融合嫦娥一号CCD影像与DEM数据的月球撞击坑自动提取和识别 总被引：3，自引：1，他引：2
针对现阶段月球撞击坑定量信息提取不足和误提取的问题,本文提出了一种融合CCD影像和DEM数据进行撞击坑的自动提取及识别的算法。（1）在太阳光照下,撞击坑的影像特征满足特定的规律,通过条件匹配在CCD影像中提取撞击坑;（2）在DEM中,利用撞击坑坑壁点的坡向值的连续性,对影像中误提取的撞击坑进行剔除;（3）在DEM中,利用撞击坑边缘点法向量的突变性,提取撞击坑边缘点并进行拟合,计算撞击坑的参数,通过坑底点云所占比例以及剖面线特征识别撞击坑的类型。经过“嫦娥一号”影像与DEM数据的验证,该算法在高纬度月球撞击坑分布均匀的区域应用效果较好。 相似文献
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遥感技术在我国水电建设前期工作中的应用 总被引：2，自引：4，他引：2
80年代以来,我国先后在雅砻江二滩、长江三峡、红水河龙滩、黄河龙羊峡、金沙江溪落渡、白鹤滩等地开展了大规模的水电站建设前期遥感调查。采用多种类、多时相、多平台遥感资料的综合解译,并辅以一定量现场验证的工作方法,进行了区域地质背景、库岸稳定性、库岸土地利用、淹没损失、库区环境等项调查,为电站可行性论证提供了更加全面和科学的资料。我国水电遥感工作的特点是：规模宏大、内容广泛、方法合理、协同攻关。随着遥感技术的进步及水电事业的发展,我国水电遥感应用存在的问题也日益突出,有待于研究解决,遥感应用水平也待不断提高。 相似文献
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跨领域地理信息的语义共享的实现依赖于对地理概念的明确理解,而由于文字的模糊性,仅从地理概念的文字描述或定义来理解往往会有一定歧义。从认知原理看,地理概念的形成更多是对其外延进行归纳,并在大脑中构建出概念范例来完成。探索了一种在地理信息领域中构造地理概念范例的方法,即通过在概念文字描述中提取确定概念范畴及外延的本体属性,通过外延和实体属性来选择实例作为表达概念显著特征的范例。通过两个构建范例的案例验证了该方法的有效性。 相似文献
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Summary Time varying coordinates of points of a geodetic network are indirectly measured by a group of measurement devices with different characteristics of accuracy in several epochs. The design of the measurement is the same in all epochs. The ratio of the characteristics of accuracy is a priori unknown. The aim is to determine an estimator of the parameters of functions modelling changes of the coordinates, confidence regions of these functions and to construct a procedure for testing linear hypotheses on time varying coordinates of a geodetic network. As the characteristics of accuracy are a priori unknown, the problem of their estimation has to be solved simultaneously. The research of rules of recent crustal movements leads to studying the mentioned model. 相似文献
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南京市城乡一体化地籍信息系统建设的若干关键技术研究 总被引：16，自引：1，他引：16
本文通过对城镇地籍信息系统和土地利用现状管理信息系统运行方式和存在问题的分析，提出了建设城乡一体化地籍信息系统的目标；进而研究了建设城乡一体化地籍信息系统的几个关键技术，并根据南京市的系统建设现状，在进行城乡一体化信息系统建设过程中进行了实践。 相似文献
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Fabio Crosilla 《Journal of Geodesy》1983,57(1-4):226-239
This paper proposes an original method of constructing a criterion matrix for the optimal design of control networks by means
of the contraction of the eigenvalues and the rotation of the eigenvectors of a covariance matrix. The rotation of the eigenvectors
is carried out by two different methods, that is through independent rotations of the pairs of the eigenvector matrix components
and through a procrustean transfomation of the same matrix. The required criterion is that the “essential eigenvector components”
must be as orthogonal as possible to the predicted direction of deformation. A Second Order Design problem is then resolved,
that is the optimization of the precision of the observations of a local free distance network to be constructed for the study
of recent crustal movements in the seismogenetic area of Friuli (Italy). The results obtained show a high degree of correspondence
for the two proposed methods of rotation if limited rotations of the eigenvectors are considered. 相似文献
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An evaluation of sampling and full enumeration strategies for Fisher Jenks classification in big data settings 总被引：2，自引：0，他引：2 
下载免费PDF全文
下载免费PDF全文 Large data contexts present a number of challenges to optimal choropleth map classifiers. Application of optimal classifiers to a sample of the attribute space is one proposed solution. The properties of alternative sampling‐based classification methods are examined through a series of Monte Carlo simulations. The impacts of spatial autocorrelation, number of desired classes, and form of sampling are shown to have significant impacts on the accuracy of map classifications. Tradeoffs between improved speed of the sampling approaches and loss of accuracy are also considered. The results suggest the possibility of guiding the choice of classification scheme as a function of the properties of large data sets. 相似文献
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空间和属性随时间变化规律的研究是时态GIS核心问题。引入面向对象方法,把地理实体抽象成为具有空间、属性和时间特性的空间对象,以空间对象的变化状态为基础,探讨了地理实体时空信息连续变化对基态修正模型的影响。通过引入基态距影响因子研究了基态修正模型改进方法,重点研究了基于面向对象基态修正模型的基态距确定、基态的建立过程和模型的存储;并具体设计了基于时间点和时间段的查询方法,为空间对象的时空数据存储、查询和历史回溯提供了基础。 相似文献
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王丽明 《测绘与空间地理信息》2002,25(2):10-11
主要研究地图的艺术性 ,为使广大读者对地图的艺术性有一个全面的了解和认识 ,主要从以下三方面进行论述 :①地图的艺术性在现代地图发展中的重要意义 ;②地图艺术性的表现形式 ;③地图艺术性的形式及其发展趋势 相似文献
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地理信息系统是一门综合性学科,实现GIS创新人才培养应从转变教育观念入手,团队教学是传统教学理念向现代教学理念转变的一种变革。本文在分析国内外教学团队建设现状基础上,提出了GIS课程教学团队的体系结构,阐述了团队工作中GIS课程体系的建设内容,研究了如何对GIS课程教学团队中教师角色进行定位,从创新平台共享、学科带头人培养、交流平台搭建和内部管理体制等方面探讨了GIS教学团队的运行机制。认为创建一支高绩效的教学团队,是GIS专业发展的动力源泉。 相似文献
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S. Ono 《Journal of Geodesy》1985,59(3):275-288
In order to solve the problems of determining the shape of a part of the earth of national or continental extent, that is,
of rigorous constituting and computing of the astrogeodetic network, it is required to determine gravimetric deflections of
the vertical with an accuracy of, say, 0″.3. For this it is adequate to carry out additional gravity surveys in the neighborhoods
of computation points, in addition to a given uniform gravity survey (normal density gravity survey).
The study offers a method to determine the optimal distribution of gravity stations in such a gravity survey, which guarantees
a given accuracy of computed gravimetric deflections of the vertical for a given statistical condition which characterizes
the variation of the gravity field. The approach used here is based on the concept of the error of representation and the
error propagation of Vening Meinesz integrals. 相似文献
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为提升区域地面监测站条件下北斗卫星定轨精度,面向日益丰富的北斗星载数据和即将实现的星间链路技术,提出了联合运用地面监测站数据、低轨卫星星载数据与星间链路数据的北斗卫星精密定轨方法。讨论了低轨卫星星载数据与星间链路数据增强对于导航卫星精密定轨的影响,重点从低轨卫星数量、轨位分布及星间链路等方面进行了仿真分析。结果表明:加入少量低轨卫星与区域监测站联合定轨即可显著提高导航卫星定轨精度约73%,钟差解算精度略有改进但不明显;同等数量且均匀分布的低轨星座,其轨位分布对联合定轨精度影响不大;加入星间链路数据可大幅提升导航卫星定轨精度,且改进效率高于低轨卫星。 相似文献
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被动微波遥感卫星具有多波段多极化观测能力,其全天候、高灵敏度特性契合了地壳活动及地震的监测分析需求。近年来,地震孕育和发生过程中的热异常遥感监测与分析得到了广泛关注。本文从星载被动微波传感器发展和地震被动微波遥感应用两方面,梳理了多波段多极化被动微波卫星遥感用于地震监测与异常识别的研究现状,剖析了微波数据选择、异常分析方法、观测粗差剔除和信息机理认知等方面的进展与不足。总结了近年微波遥感地震应用的研究进展,阐明了多波段多极化被动微波卫星遥感用于地震异常识别的科学逻辑与复合链条。提出了地震遥感的两个前沿探索方向,即地震微波异常的可靠识别、地应力场变化微波遥感的信息物理。指出了遥感-岩石力学基础试验研究和地震遥感综合分析层面亟待解决的关键问题。进而呼吁,多学科联合、交叉乃至融合是地震遥感科学与技术向纵深发展的必由之路。 相似文献
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文章在综合研究前人相关文献基础上,以1∶5 000 000和1∶10 000 000两种比例尺道路网数据为依据,给出了全国各主要省市道路网分形维数的大小及变化趋势,通过比较分析验证了全国各主要省市道路网分形特征的客观存在,并指出了今后的研究方向。 相似文献
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在田间栽种玉米,并按氮、磷肥的不同施用量分为10种情况处理。在不同生长期进行了生长形态指标测量和活体叶片的荧光光谱与激光诱导荧光光谱测量,并测试了叶片浸出液的荧光光谱。结果表明,不同的施肥条件.不仅使玉米在长势上有所反映,而且还会引起光合作用效率和叶绿素含量等的变化,因而导致了玉米叶片荧光光谱的变化。利用440,550,685nm等处的荧光强度可探测玉米的养分供应状况,当利用它们的比值时,表征更为明显。这就为遥感监测玉米的长势和估产提供了新的途径和可靠依据。从玉米的需肥情况、农时、荧光光谱的差异性以及遥感的可行性来看,在拔节期是遥感监测的最佳时期。 相似文献