共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
等高线在地形图测绘中是表达地貌特征的重要符号。为保证拓扑正确性,常需要进行等高线与高程点间的点线关系正确性检测。目前已有的点线矛盾检测算法主要有等高线不规则三角网(TIN)法、射线法等,这些算法均存在漏检测或错检测等问题。本文基于已有方法,提出了一种改进的高程点-不规则三角网(TIN)射线法,该方法结合了TIN和射线法的优点,并互为补充。在进行点线矛盾检测时,加入数据预处理功能,先使用等高线TIN法做一次初筛,再利用高程点TIN射线法进行精准识别,能有效降低错漏率。经测试表明,此法不仅能够更有效筛选出点线矛盾点,还具有运算效率高、方法简单易行等特点,能够满足实际的生产需要。 相似文献
3.
4.
在精密定位中,GNSS接收机天线相位中心变化是必须进行改正的影响因素。目前成熟的微波暗室法和自动机器人法,对于一般用户而言,不具备相关实验条件,而野外相对法相对简单、易操作。为此,本文利用相对检测法,对GNSS接收机天线相位中心变化进行检测。实例表明,此方法可获得精度优于±3 mm的检测结果,因此可利用此方法对其他类型天线PCV值进行检测,也可借鉴此方法对北斗接收机天线相位中心变化进行检测。同时论文分析了影响检测精度,提出了有益改进建议。 相似文献
5.
基于带权点法向量的LiDAR数据屋顶检测方法 总被引:1,自引:0,他引:1
提出了一种基于带权点法向量的LiDAR数据屋顶检测方法。通过利用点和其邻接点构成的面法向量进行峰值统计,检测屋顶面。检测过程中同时考虑每个点法向量的权值,从而确定每个点对面的贡献,一定程度上消除了噪声的影响,提高了小面积屋顶检测的准确程度。同时,采用多阈值进行屋顶面检测,能够检测大小不同的面。通过实验验证了本算法的有效性。 相似文献
6.
控制点粗差检测是保证光学影像自动几何精校正精度的重要环节。将数据探测法、抗差估计法和随机抽样一致性法(RANSAC)三种经典的粗差检测方法应用于光学影像自动几何精校正的控制点粗差检测中,详细阐述了三种方法检测控制点粗差的方法和流程,并在控制点粗差率为10%、20%、30%和60%的情况下,利用实际光学卫星影像分别对三种方法展开控制点粗差检测实验。实验结果表明RANSAC相比数据探测法和抗差估计法对粗差率的敏感性最小,具有更强的鲁棒性,更加适用于光学影像几何自动精校正中控制点的粗差检测。 相似文献
7.
8.
本文介绍了屏幕观测对比法,仪器观测对比法,软件自检测法,高分辨率地等四种用于检测实时单点匹配精度的方法,并利用上述检测了实时CCD影像和卫星影像的匹配成果。 相似文献
9.
四种基于像元的地表覆盖变化检测方法比较 总被引:1,自引:0,他引:1
目前遥感影像变化检测方法很多,但各种方法的适用性各不相同。鉴于灰度差值、NDVI差值、灰度比值、主成分分析法在地表覆盖变化检测中应用广泛,文章从数据更新的角度对这4种方法进行了比较;在分析比较这4种方法的单一变化检测精度、检测结果的相同性、相异性的基础上探索了适合于30m分辨率TM地表覆盖变化检测的组合方法。实验结果表明,在地表覆盖变化检测中,有效组合方法能够取得比单一变化检测方法更好的效果;比值法并NDVI差值法并PCA差异法的检测结果中包含了4种单一检测方法所检测出的全部变化像元,达到了最高的生产者精度,比较适合于地表覆盖数据更新制图应用。 相似文献
10.
一种高精度的TV-L~1光流算法 总被引:1,自引:0,他引:1
介绍了一种求解光流方程的新型数值方法。针对变分光流法无法有效检测由于间断、遮挡等造成的错误光流分量的缺陷,引入了光流有效性检测技术,同时提出了邻域修正法来修正错误分量。并采用结构纹理分解、加权中值滤波、金字塔等高效的光流技术,进一步增强了光流算法的精确性与实用性。 相似文献
11.
12.
A. A. Lyutyy 《地理信息系统科学与遥感》2013,50(2):127-139
The author continues development of his concept of cartography as the “language of the map,” an earlier paper of this subject appearing in translation in M.S.R.S., 1985, No. 1. Although the term language has been widely used to describe cartographic communication, current theory fails to incorporate aspects of the language which provide for a comprehensive understanding of its structure and function. In particular, the language of the map and its symbolic elements cannot be explained reflexively by methods and rules of symbol and map design, since these elements were developed not before but after the existence of the language. The language of the map thus is proposed as the mechanism which provides for replicability or duplication in the way a system of mapmaking-map use functions (under diverse conditions, purposes, historical periods, and levels of training of users) through its different methods, models, and norms. Translated from: Geografiya i prirodnyye resursy, 1985, No. 3, pp. 142-151. 相似文献
13.
M. J. Miles 《The Photogrammetric Record》1968,6(32):196-201
The theory of the solution of the stereogram is developed from the condition that the vector triangle, formed by the base-line and the two rays from the perspective centre to a common model point, shall be in equilibrium. Using this approach the unique definition of a point in the model follows naturally from the solution of the relative orientation problem. 相似文献
14.
AbstractWe have seen that a few constellation-names used by us to-day make their appearance as far back as the Homeric poems, while the star-names Sirius and Arcturus are found in the works of Hesiod. We saw no reason to suppose that these early poets knew no names for other groups. They mentioned only those conspicuous heavenly objects that might occur in any general literature, as for example in the Old Testament books of Job and Amos. There are sporadic references to constellations in the extant works of the great Greek tragedians of the fifth century B.C., but these give us few additions to the Homeric list'. It is not till we come to the special literature of the subject that constellation-names appear in any quantity. The first specialist whose name stands out is the mathematician Eudoxus of Cnidus, a disciple of Plato, who lived in the first half of the fourth century B.C. He wrote a prose work entitled the “Phaenomena”, which, though unfortunately lost, was rendered into verse by the poet Aratus about 275 B.C. 相似文献
15.
AbstractThe order of the constellations in the following catalogue is that of the list in Ptolemy's “Almagest, except that the modern groups in the northern hemisphere are inserted after Ptolemy's northern and before his zodiacal constellations, while the modern groups in the southern hemisphere follow the last of his list. The constellation-name in italic capitals is the Latin form in general use. It is followed by the English translation where necessary and by the French and German versions. The Greek and Arabic names, with their authorities, are then given and translated where they differ in meaning from the Latin. 相似文献
16.
油气藏中的挥发组份通过上覆地层微裂隙渗漏到地表,形成烃类物质地球化学异常晕。遥感作为一门新技术,已有效地应用到地表油气微渗漏异常的探测。本文主要介绍国外在因烃类微渗漏而造成的油气田地表土壤变化、岩石蚀变和地植物异常等方面的研究现状,以及国外在探索其形成机制方面的进展,并介绍国外石油遥感专家利用各种遥感手段进行烃类微渗漏探测的有效方法,望能达到推动我国石油遥感研究进一步深入与发展的目的。 相似文献
17.
标尺误差是精密水准测量的一项重要误差来源。其中由于温度变化而引起因瓦带的长度变化,是使用因瓦标尺带来的误差之一。国内外有关文献曾对此进行过深入的研究。我国过去在精密水准测量时,未测定所用因瓦标尺的综合膨胀系数,故在一等水准网平差中未对观测高差加标尺温度改正。本文主要针对将要开始的精密水准复测,讨论标尺的温度改正问题和我们的试验结果。 相似文献
18.
19.