共线条件方程在建筑物比高求解中的应用     

李二森  张保明  郭海涛  郑明清  徐安建  赵建超 《海洋测绘》2008,28(1):46-48

高度信息作为人工地物的重要属性信息，在军事和民用上都具有很高的利用价值。针对人工地物高度提取的发展现状及存在的主要问题，对单张航片利用共线条件方程确定人工地物比高方法的原理和技术进行了研究，并进行了实验，验证了方法的可行性。  相似文献   

The journal Communications in Numerical Methods in Engineering with Biomedical Applications becomes the International Journal for Numerical Methods in Biomedical Engineering (IJNMBE) from 1st January 2010     

Perumal Nithiarasu  Rainald Löhner 《国际地质力学数值与分析法杂志》2009,33(16):1769-1770

Communications in Numerical Methods in Engineering, founded by Roland W. Lewis in 1985, will change its title to the ‘International Journal for Numerical Methods in Biomedical Engineering’ and has a revised Aims and Scope. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Nonlinear numerical simulation on extreme-wave kinematics     

NING Dezhi  TENG Bin  LIU Shuxue 《海洋学报(英文版)》2009,28(3):75-81

A fully nonlinear numerical model based on a time-domain higher-order boundary element method (HOBEM) is founded to simulate the kinematics of extreme waves. In the model, the fully nonlinear free surface boundary conditions are satisfied and a semi-mixed Euler-Lagrange method is used to track free surface; a fourth-order Runga-Kutta technique is adopted to refresh the wave elevation and velocity potential on the free surface at each time step; an image Green function is used in the numerical wave tank so that the integrations on the lateral surfaces and bottom are excluded. The extreme waves are generated by the method of wave focusing. The physical experiments are carried out in a wave flume. On the horizontal velocity of the measured point, numerical solutions agree well with experimental results. The characteristics of the nonlinear extreme-wave kinematics and the velocity distribution are studied here.  相似文献   

a′Trous小波变换与PCA变换相结合的遥感影像融合分析     

林卉  景海涛  张连蓬 《地球信息科学学报》2008,10(2):269-272

随着高分辨率遥感卫星的产生,传统的融合技术难以达到较好的融合效果,如主成分分析(PrincipalComponents Analysis)变换融合受到融合区域的限制,而传统的小波融合(Wavelet Transformation)算法由于高频直接替换,导致了一定程度的光谱失真,由此本文在分析主成分分析变换和a′Trous小波变换(WT)的基础上,以QuickBird全色和多光谱数据为实验数据,提出了一种将两者相结合的遥感影像融合方法,通过与其他融合方法的定量和视觉比较,结果表明该方法能得到更好的融合效果。  相似文献   

国土资源卫星遥感数据应用评估系统构建   总被引：1，自引：0，他引：1  

甘甫平  尤淑撑  邱振戈  于海洋 《国土资源遥感》2009,20(1):7-12

从国土资源应用出发，在“指标-模拟-评估-指标修改-模拟-评估”模式的基础上，构建了由软件系统、硬件系统、技术标准和技术方法4部分组成的评估系统，建立了较为完整的卫星数据应用评价技术方法体系，为实现在卫星研制初期就真正开展天地一体的我国卫星研制和应用的发展路线，提供了新的思路和技术体系支撑。  相似文献   

CBERS-02B星数据融合方法评价   总被引：2，自引：0，他引：2  

于海洋  甘甫平  邱振戈 《国土资源遥感》2009,20(1):64-68

CBERS—02B星(以下简称02B星)多光谱CCD数据与全色HR数据空间分辨率相差较大，给图像融合带来一定困难。在对IHS变换、主成分分析变换、Brovey 变换、GS变换等融合算法分析的基础上，利用02B星数据进行了融合试验。通过对试验结果的目视评价与定量分析发现，PC变换和GS变换方法融合图像纹理信息较清晰，光谱保真度较好。在GS变换融合中，可利用02B星CCD相机第5波段模拟GS变换的低分辨率输入，融合结果统计值优于PC变换。  相似文献   

基于多源遥感数据的区域生态系统服务价值年际动态监测 ——以中原城市群为例   总被引：2，自引：0，他引：2  

王万同  孙汀  王金霞  付强  安传艳 《地理科学》2019,39(4):680-687

通过对多源遥感数据在生态系统服务价值（ESV）遥感模型中的尺度效应分析,选择满足最佳空间分辨率和长时间序列的遥感数据,对中原城市群区域2001~2013年的ESV实现了逐年逐像元水平的动态监测。结果表明：该区应用于遥感模型输入数据的最适空间分辨率为30~1 000 m,相对于30 m尺度,其他尺度估算结果的相对偏差均小于0.4%;结合年际动态监测的需求,选择了MODIS数据产品（空间分辨率500 m,时间尺度1 a）作为遥感模型的最佳数据源;研究区ESV总值在研究期内整体上呈显著增长趋势,增速约为8.6亿元/a,但在持续增长过程中经历了3次波动,且表现得越来越剧烈;在空间上,研究区ESV多年均值呈现出明显的不均衡性,表现为从西南向东部递减的趋势。研究表明此方法简单易行,初步实现了区域ESV年际动态监测遥感模型的准业务化运行。  相似文献   

Comparison of flow patterns in the near wake of a circular cylinder and a square cylinder placed near a plane wall     

X.K. Wang  S.K. Tan 《Ocean Engineering》2008,35(5-6):458-472

The flow patterns in the near wake of a cylinder (either circular or square in shape, D=25 mm) placed in the proximity of a fully developed turbulent boundary layer (thickness δ=0.4D) are investigated experimentally using particle image velocimetry (PIV). The effects of changing the gap height (S) between the cylinder bottom and the wall surface, over the gap ratio range S/D=0.1–1.0, have been investigated. The results show that both the ensemble-averaged and instantaneous flow fields are strongly dependent on S/D. The flow patterns for the two types of cylinders share many similarities with respect to the change in S/D, such as the reduced recirculation length and increased velocity fluctuation in the near wake with increasing S/D, as well as the trend of suppression of vortex shedding at small S/D and onset of vortex shedding at large S/D. However, developments of the shear layers, in terms of wake width, flow curvature, etc., are considerably different for these two types of cylinders. In general, the wake development and momentum exchange for the square cylinder are slower those for the circular cylinder at the same gap ratio. Correspondingly, it is shown that the periodic vortex shedding is delayed and weakened in the case of square cylinder, as compared to that of the circular cylinder at the same S/D.  相似文献   

基于ERDAS的SPOT5卫星影像正射校正方法研究   总被引：2，自引：0，他引：2  

刘善伟  万剑华  张杰  马毅  任广波 《海洋测绘》2008,28(4):30-33

海岛海岸带卫星遥感调查与评价项目以高分辨率卫星遥感影像数据为基础。项目区块地形有一半为山地和丘陵，地形起伏较大，常规的几何校正难以消除因地形起伏引起的影像几何变形，必须进行正射校正。根据现有数据特点和项目要求，提出了可行的正射校正流程，基于SPOT5物理模型对融合影像进行正射校正，实验校正结果完全满足精度要求。  相似文献   

Mapping of aggregated floodplain plant communities using image fusion of CASI and LiDAR data     

Jochem Verrelst  Gertjan W. Geerling  Karle V. Sykora  Jan G.P.W. Clevers 《International Journal of Applied Earth Observation and Geoinformation》2009

Combined optical and laser altimeter data offer the potential to map and monitor plant communities based on their spectral and structural characteristics. A problem unresolved is, however, that narrowly defined plant communities, i.e. plant communities at a low hierarchical level of classification in the Braun-Blanquet system, often cannot be linked directly to remote sensing data for vegetation mapping. We studied whether and how a floristic dataset can be aggregated into a few major discrete, mappable classes without substantial loss of ecological meaning. Multi-source airborne data (CASI and LiDAR) and floristic field data were collected for a floodplain along the river Waal in the Netherlands. Mapping results based on floristic similarity alone did not achieve highest levels of accuracy. Ordination of floristic data showed that terrain elevation and soil moisture were the main underlying environmental drivers shaping the floodplain vegetation, but grouping of plant communities based on their position in the ordination space is not always obvious. Combined ordination-based grouping with floristic similarity clustering led to syntaxonomically relevant aggregated plant assemblages and yielded highest mapping accuracies.  相似文献