数字高程模型的野外采样密度与精度

本文研究了通过野外采样构成数字高程模型的精度与采样点密度的关系,通过实验论证,提出了地貌数据的采样方法、采样密度和内插方法的初步看法,并进行了相应的精度分析。     

数字高程模型精度评价及其问题探讨

分析了数字高程模型（DEM）精度评价中检查点“中误差”法的局限及DEM产品的实际质量问题,提出了采用等高线回放法以逼近误差的概念,以衡量DEM全域出现的最大误差。     

MATHEMATICAL MODELS OF THE ACCURACY OF DIGITAL TERRAIN MODEL SURFACES LINEARLY CONSTRUCTED FROM SQUARE GRIDDED DATA

This paper presents two mathematical models of the accuracy of digital terrain model (DTM) surfaces which have been linearly constructed from square gridded data, respectively with and without additional feature specific data. In these models, the accuracy of DTM surfaces is expressed as a function of a few parameters, such as slope angle, grid interval or the accuracy of raw data, which are familiar to practitioners in photogrammetry and other mapping related disciplines. These models are in a form similar to the conventional formulae for contour map accuracy and they are compared with experimental test results.     

QUALITY CONTROL OF PHOTOGRAMMETRICALLY SAMPLED DIGITAL ELEVATION MODELS

The object of this paper is to study the geometric accuracy of photogrammetrically sampled digital elevation models (DEMs)obtained by using an on line graphical DEM editor. As a reference, DEMs obtained by regular grid measurements have been used. Three different test areas are used in the study, each representing different ground types and degrees of homogeneity. The DEMs have been evaluated with respect to their standard errors in elevation, slope and curvature. The results show that the standard errors are not improved by using the on line DEM editor. It is also demonstrated that an increased point density decreases the standard error in elevation while its effect on the standard error in slope is limited. The standard error in curvature is almost independent of the point density.     

THEORETICAL MODELS OF THE ACCURACY OF DIGITAL TERRAIN MODELS: AN EVALUATION AND SOME OBSERVATIONS

This paper is an attempt to evaluate existing theoretical models for the accuracy of digital terrain models (DTM) both through a theoretical analysis and by experimental tests. In order to extend the discussion, some comments on the general form in which a DTM accuracy model should be constructed are also made and a possible solution is offered.     

QUALITY ASSESSMENT OF DIGITAL ELEVATION MODELS PRODUCED BY AUTOMATIC STEREOMATCHERS FROM SPOT IMAGE PAIRS

A number of published steromatching algorithms have been implemented and tested on SPOT images of areas for which gridded digital elevation models (DEMs) are available with spacings of 80 m or less, as well as ground control checkpoints. Results are presented for comparison of stereomatched output with the DEMs as well as an analysis of the errors arising and their causes. Results are discussed for planimetrically geocoded and epipolar resampled data. An error budget describing effects due to orientation, feature localisation and matching are discussed and conclusions drawn for future work in this area.     

应用数字图像处理技术处理数字高程模型数据和与数字高程模型数据相结合的遥感信息

本文介绍了数字图像处理技术在处理数字高程模型数据和遥感信息与数字高程模型数据相结 合的综合分析方面的应用；说明了实现人工阴影和人工立体观察像对的方法的基本原理及其在处 理数字高程模型数据上的应用；介绍了为提高遥感图像的可解译性,把遥感信息与数字高程模型 相结合,制作遥感图像的人工立体观察像对和立体透视图像的方法技术。     

THE SCHEME FOR THE DATABASE BUILDING AND UPDATING OF 1:10 000 DIGITAL ELEVATION MODELS

The National Bureau of Surveying and Mapping of China has planned to speed up the development of spatial data infrastructure (SDI) in the coming few years. This SDI consists of four types of digital products, i. e., digital orthophotos, digital elevation models,digital line graphs and digital raster graphs. For the DEM,a scheme for the database building and updating of 1:10 000 digital elevation models has been proposed and some experimental tests have also been accomplished. This paper describes the theoretical (and/or technical)background and reports some of the experimental results to support the scheme. Various aspects of the scheme such as accuracy, data sources, data sampling, spatial resolution, terrain modeling, data organization, etc are discussed.     

基于DEM的遥感数据复原方法研究

介绍了一种基于数字高程模型（DEM）的遥感数据复原新方法。此方法将地形因子作为最主要的作用因子，不考虑卫星传感过程中的随机影响。首先，根据基础地理数据，按其等高线层生成DEM； 然后，利用DEM，通过实测样点、DEM和经过纠正的遥感数据的信息融合，进行遥感数据中像元样点的坡度、坡向分析，建立DEM与遥感信息的相关关系模型，以数学统计方法描述地形因子对遥感数据的作用机理； 最后，进行逐像元的遥感信息复原(归一化)。结果表明，该方法具有较好的信息复原效果，可消除或减少地形对遥感数据的影响，增强遥感技术在山区复杂地形下的实用性。     

基于PALSAR数据的DEM提取方法研究

针对PALSAR Level 1.1数据,研究使用NASA/JPL提供的开源干涉软件包ROI_PAC Version 3.0提取DEM.ROI_PAC的目前版本只能处理Level 1.0数据,因此,文章在分析了ROI_PAC软件包处理流程的基础上,提出处理Level 1.1数据的方法,并用PALSAR Level 1.1数据对该方法做了验证.干涉重建DEM与参考DEM的对比结果表明,二者的差异均值为0.27 m,标准差为±9.24 m,80%像元点的高程误差在±10 m以内.     

ON THE MEASURE OF DIGITAL TERRAIN MODEL ACCURACY

In digital terrain model (DTM) production, one important concern is the accuracy and a comprehensive measure of DTM accuracy is of significance. In this paper, the existing measures are evaluated; the potential measures are also discussed and, finally, a more comprehensive measure is recommended.     

空间数据精度的检查和评价方法研究

从GIS空间数据精度出发,论述了空间数据误差的影响因素,提出空间数据精度的评价方法和确定空间数据精度实际检查过程中应注意的问题,并以实际工作成果说明本文提出的空间数据精度检查及评价的效果。     

从数字深圳看三维城市模型数据生产流程及技术

分析了在数字深圳工程中三维城市模型数据的生产流程及技术，从三维地物模型航测数据的采集开始，至最后工作区的合并与数据的提交，说明了数字城市雏形的建设过程。     

微机遥感影像数字高程自动提取技术

本文研究了利用航天遥感影像自动提取数字高程模型(DEM)的方法技术,建立了一整套利用SPOT影像提取DEM的方案。该方案改进和发展了多级影像匹配策略,采用了多种适合于微机的快速算法。根据该方案开发了相应的微机软件系统。试验结果表明,整套技术方案和算法可行,结果具有较高的精度和可靠性,软件运行速度较快,有较强的实用性。     

基于灰关联分析的GPS高程拟合加权平均函数模型权函数优选

基于灰色系统理论的灰关联分析方法,提出了权函数的优选方法,实例分析表明其具有较好的实用价值.     

SYNTHETIC-APERTURE RADAR IMAGERY IN THE CONSTRUCTION OF DIGITAL TERRAIN MODELS

An analysis is made of conditions believed to be optimum for a stereoscopic survey of the Earth's surface by a synthetic-aperture radar on board a spacecraft. Variants for construction of an orbiting stereosystem and factors contributing to a radiometric mismatch of stereopair images are examined. Analysis and choice of optimum conditions for a stereophotogrammetric survey are oriented toward facilitating the computer processing of radar images for the purpose of obtaining digital terrain models.     

基于规则格网DEM自动提取地性线的一种简便方法

给出了一种基于规则格网ＤＥＭ自动提取地性线的简便方法,阐述了其具体实现过程,实验表明其不仅易于实现,而且还是一种基本上对大部分常规地形的ＤＥＭ均适用的方法。     

THE ACCURACY OF VISUAL DETERMINATIONS OF STATISTICAL CHARACTERISTICS FROM MAPS

The authors address a range of issues connected with the visual representation and interpretation of statistical data on maps. Attention is focused on common behaviors of map users in determinations of various characteristics of map symbols. Results are reported from experiments testing the relationship between the accuracy of obtaining quantitative information on a map with the total number of symbols and number of scale levels [size classes] employed, the use (or non-use) of color in the symbolization scheme, etc. Translated by Larry Richardson, Los Angeles, CA 90039 from: Izvestiya Vsesoyuznogo Geograficheskogo Obshchestva, 1989, No. 4, pp. 345–351.     

两种坐标转换模型的精度比较

本文介绍了两种常用的坐标转换模型和最小二乘配置坐标转换方法,并以徐州市基础测绘北京54和西安80平面坐标的转换为例,比较了二维多项式变换模型和相似变换模型的精度。最后分析了两种模型的优劣。同时,提出了利用QR矩阵分解法来解决最小二乘法矩阵求逆导致的数值不稳定问题。