利用ASTER立体像对提取相对DEM及正射影像地图制作

本文探讨在PCIGeomatica软件支持下,应用四川省泸州地区ASTER立体像对数据自动提取DEM及其正射影像地图制作。通过与当地实测地形图(1∶50000)比较,表明在平坦地区ASTER DEM与实测地形图吻合很好;在高程变化较大的区域由于太阳高度、方位影响和ASTER后视成像存在着较大的叠掩和阴影效应,ASTER DEM和实测DEM存在一些差异,但总体上可以满足中小比例尺(1∶500,000到1∶1000,000)地图应用。ASTER的应用为DEM的快速提取和正射影像地图制作提供了一种新的途径。     

ALOS-PRISM立体像对提取DEM的应用研究

本文使用ALOS-PRISM高分辨率立体像对数据提取DEM;针对DEM精度评定过程中地形单一的问题,文中着重分析了DEM在不同地形条件下的精度情况,通过与1∶50 000实测DEM比较分析,结果表明在无植被覆盖的平原地区DEM精度最高,高程中误差可以达到4.46m;其次是城区,山区最差,与同类卫星产品相比该精度已有很大的提高,因此ALOS-PRISM的应用可以为我们快速获取高精度的DEM提供一种新的途径。     

ASTER 立体影像提取DEM的研究

介绍了具有同轨立体测图能力的ASTER传感器观测系统,及其立体影像生成DEM的算法和DEM的编辑方法,展示了ASTER立体影像生产DEM的实验结果,并以试验结果说明,其精度可以满足绘制1：100000～1：250000比例尺地形图要求。     

基于ASTER立体像对提取数字高程模型的试验研究

ASTER是一种新型高分辨率多光谱传感器,其在可见光波段的准实时立体像对获取模式可以用于地面数字高程模型的提取.介绍ASTER立体像对提取DEM的基本原理和数据处理流程,并利用ASTER立体影像进行南极内陆冰盖DEM提取的试验,取得较好的结果,为今后ASTER数据在此方面的应用提供示范.     

基于立体像对提取DEM的方法研究与实践

DEM作为重要的基础空间数据,在城市规划、建设方面发挥着重要作用。本文利用INPHO数字摄影测量系统,结合高分航空立体像对,探索山地大面积区域DEM数据获取的技术方法,同时对其精度进行了验证评价,为地理国情普查等项目的 DEM生产提供参考。     

含有DEM误差的立体正射影像对上高程量测精度探讨

在DEM支持下,通过引入投影视差光线,以数字正射影像为基础,制作立体辅助影像,并与原正射影像共同构建正射立体影像对,产生与实地相似的几何模型,进行立体观察与量测,可以量测地貌高程,是另外一种构建立体三维环境的思路.然而生成正射影像和辅助影像的原始DEM是含量有误差的.这种误差是否会对产生的立体正射影像对的高程量测结果产...     

不同软件在ASTER数据中提取DEM的精度对比

利用3个不同的软件对四川省龙门山中段ASTER 15 m分辨率的立体像对进行了DEM提取,并对其精度进行了初步评价。分别使用立体测量法和干涉测量法提取DEM,并通过检验点法和剖面线法对比分析。结果表明,利用ERDAS的干涉测量法提取出的DEM效果较好,高程精度可达30 m,对后续数据深挖掘和高层次地形分析具有应用价值。     

利用ASTER立体像对提取Grove山地区相对DEM及精度分析

在无地面控制点的情况下,利用ASTER L1A级数据中的两个波段(3N,3B)进行南极Grove山地区立体测量,将其结果与在2000年由中国第16次南极科学考察队GPS实测的数据和InSAR技术生成的DEM进行详细比较分析。结果证明利用ASTER立体影像提取DEM能保证较高的精度,能够用于南极科学研究。     

基于SPOT 5异轨立体像对提取DEM试验与精度评估

介绍了异轨立体像对提取DEM的基本原理和数据处理流程,利用两景影像进行了DEM提取试验,分析了结果的精度,提出了利用卫星立体影像提取DEM这一方法的发展方向。     

基于资源三号卫星立体像对的DEM提取实验及其应用——以拉萨市城关区为例

利用测绘卫星立体像对提取DEM效率高、精度高。本实验的主要目的是进行资源三号测绘卫星立体像对高海拔地区DEM提取实验,比较正视、前视及后视3种视角全色影像不同组合情况的立体像对所提取DEM的效果,以拉萨市城关区为实验区,并将实验结果与SRTMDEM进行比较。实验结果显示,正视与前、后视组成的立体像对提取的DEM效果相当,均好于前视、后视全色影像组成的立体像对提取得到的DEM,拉萨市城关区空间分辨率可达10 m,效果良好,可为城市地质灾害评价等提供基础数据。     

Mapping from ASTER stereo image data: DEM validation and accuracy assessment

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on-board the National Aeronautics and Space Administration's (NASA's) Terra spacecraft provides along-track digital stereo image data at 15-m resolution. As part of ASTER digital elevation model (DEM) accuracy evaluation efforts by the US/Japan ASTER Science Team, stereo image data for four study sites around the world have been employed to validate prelaunch estimates of heighting accuracy. Automated stereocorrelation procedures were implemented using the Desktop Mapping System (DMS) software on a personal computer to derive DEMs with 30- to 150-m postings. Results indicate that a root-mean-square error (RMSE) in elevation between ±7 and ±15 m can be achieved with ASTER stereo image data of good quality. An evaluation of an ASTER DEM data product produced at the US Geological Survey (USGS) EROS Data Center (EDC) yielded an RMSE of ±8.6 m. Overall, the ability to extract elevations from ASTER stereopairs using stereocorrelation techniques meets expectations.     

Accuracy improvement of ASTER stereo satellite generated DEM using texture filter

The grid DEM(digital elevation model) generation can be from any of a number of sources:for instance,analogue to digital conversion of contour maps followed by application of the TIN model,or direct elevation point modelling via digital photogrammetry applied to airborne images or satellite images.Currently,apart from the deployment of point-clouds from LiDAR data acquisition,the generally favoured approach refers to applications of digital photogrammetry.One of the most important steps in such deployment i...     

一种模拟纠正影像的SAR立体影像匹配方法

针对常规SAR影像匹配方法在地形起伏较大区域无法获取理想的SAR立体影像匹配结果的问题,该文提出了一种基于模拟纠正影像的SAR立体影像匹配方法。利用观测区域粗分辨率DEM进行SAR影像模拟,进而获取几何纠正SAR影像,在几何纠正SAR影像上实现影像匹配,等效于常规基于灰度影像匹配中进行的影像粗配准工作,并且相比于常规粗配准,该等效粗配准过程能够均衡地顾及到整幅影像的像元,最终实现了地形起伏较大区域的高精度SAR立体影像匹配。采用COSMO-Skyped影像数据进行了实验,实验结果表明,匹配精度达到了3个像素左右,比常规的基于灰度影像匹配方法有较大提高,能够有效解决地形起伏较大区域SAR立体影像匹配问题。     

Evaluation of vertical accuracy of open source Digital Elevation Model (DEM)

Digital Elevation Model (DEM) is a quantitative representation of terrain and is important for Earth science and hydrological applications. DEM can be generated using photogrammetry, interferometry, ground and laser surveying and other techniques. Some of the DEMs such as ASTER, SRTM, and GTOPO 30 are freely available open source products. Each DEM contains intrinsic errors due to primary data acquisition technology and processing methodology in relation with a particular terrain and land cover type. The accuracy of these datasets is often unknown and is non-uniform within each dataset. In this study we evaluate open source DEMs (ASTER and SRTM) and their derived attributes using high postings Cartosat DEM and Survey of India (SOI) height information. It was found that representation of terrain characteristics is affected in the coarse postings DEM. The overall vertical accuracy shows RMS error of 12.62 m and 17.76 m for ASTER and SRTM DEM respectively, when compared with Cartosat DEM. The slope and drainage network delineation are also violated. The terrain morphology strongly influences the DEM accuracy. These results can be highly useful for researchers using such products in various modeling exercises.     

基于等高线生成DEM的内插算法及其精度分析

以等高线为例,探讨了利用地图等高线矢量化生产DEM内插算法,并分析了各种方法的精度及适用范围。     

中国及周边区域ASTER GDEM与SRTM DEM高程对比分析及互补修复

本文分析了ASTER GDEM和SRTM DEM的获取方式,通过对两者在中国及周边区域高程的对比分析,得出两者高程间存在系统误差,前者高程比后者平均低4.9m.ASTER GDEM在许多区域特别是水域及高山区常存在明显粗差;SRTM DEM在特别是高山区域会出现空白区域,但其有效区域层次清晰、细节分明,无明显粗差,可靠性高 经过填补及高差约束限制修复,生成了无空白区域的SRTM DEM和可靠性更高的ASTER GDEM.     

SPOT5 HRS生成DEM精度评价分析

描述了从SPOT5HRS生成DEM的不同方法,将来源于SPOT5三立体影像的不采用控制点情况下生成的DEM与高精度的参考DEM对比,对HRS生成的DEM进行精度分析评价,证明了在我国西部无图区利用SPOTHRS立体像对生成DEM的可行性。     

Comparative evaluation of horizontal accuracy of elevations of selected ground control points from ASTER and SRTM DEM with respect to CARTOSAT-1 DEM: a case study of Shahjahanpur district,Uttar Pradesh,India

Digital elevation model (DEM) data of Shuttle Radar Topography Mission (SRTM) are distributed at a horizontal resolution of 90 m (30 m only for US) for the world, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) DEM data provide 30 m horizontal resolution, while CARTOSAT-1 (IRS-P5) gives 2.6 m horizontal resolution for global coverage. SRTM and ASTER data are available freely but 2.6 m CARTOSAT-1 data are costly. Hence, through this study, we found out a horizontal accuracy for selected ground control points (GCPs) from SRTM and ASTER with respect to CARTOSAT-1 DEM to implement this result (observed from horizontal accuracy) for those areas where the 2.6-m horizontal resolution data are not available. In addition to this, the present study helps in providing a benchmark against which the future DEM products (with horizontal resolution less than CARTOSAT-1) with respect to CARTOSAT-1 DEM can be evaluated. The original SRTM image contained voids that were represented digitally as ?140; such voids were initially filled using the measured values of elevation for obtaining accurate DEM. Horizontal accuracy analysis between SRTM- and ASTER-derived DEMs with respect to CARTOSAT-1 (IRS-P5) DEM allowed a qualitative assessment of the horizontal component of the error, and the appropriable statistical measures were used to estimate their horizontal accuracies. The horizontal accuracy for ASTER and SRTM DEM with respect to CARTOSAT-1 were evaluated using the root mean square error (RMSE) and relative root mean square error (R-RMSE). The results from this study revealed that the average RMSE of 20 selected GCPs was 2.17 for SRTM and 2.817 for ASTER, which are also validated using R-RMSE test which proves that SRTM data have good horizontal accuracy than ASTER with respect to CARTOSAT-1 because the average R-RMSE of 20 GCPs was 3.7 × 10^?4 and 5.3 × 10^?4 for SRTM and ASTER, respectively.