TerraSAR-X影像直接地理定位方法研究   总被引：2，自引：0，他引：2  

魏钜杰  张继贤  黄国满  庞蕾 《测绘通报》2009,(9)

开展高精度直接定位算法研究对促进SAR影像的广泛应用具有重要意义。针对新型高分辨率雷达卫星TerraSAR-X影像,在无任何地面控制支持下采用距离多普勒构像模型及地球物理模型,通过线性化及最小二乘平差原理迭代求解目标点的位置矢量,并利用影像元数据文件中提供的影像四个角点和中心点的地理坐标作为控制点,消除定位结果中存在的系统误差。在利用陕西宝鸡地区的TerraSAR-X影像试验中,将其定位结果与当地1∶1万地形图上选取的控制点进行比较,获得的平均平面定位精度约±63m左右,表明该算法合理可行,具有一定的实用性。  相似文献   

矢量图形与影像图像一体化实现   总被引：3，自引：0，他引：3  

倪建华  秦佐 《四川测绘》2009,32(3):103-105

本文在阐述影像金字塔相关理论（构建方法、影像切割等）的基础上,采用VC2005编程实现了在同一GIS系统中进行矢量数据和栅格数据叠加显示的功能模块。该模块可确定是否加载影像,并根据当前矢量图显示范围自动加载不同分辨率的影像图。  相似文献   

CLSM技术应用于化石硅藻微构造的尝试研究   总被引：2，自引：1，他引：1  

王金星  李家英 《地球学报》2007,28(1):79-85

首次采用激光扫描共聚焦显微系统(Confocal Laser Scanaing Microsystem)的新方法对西藏化石硅藻进行了微构造的尝试研究,通过对标本不同层面的系列扫描和三维重组立体图像的观察,揭示了采自西藏阿里地区和山南地区湖相沉积剖面的化石硅藻的微构造及形态特征,发现了某些对硅藻分类、示相特征的新标识,并在CLSM技术的应用方面获得了新的认识.  相似文献   

Bifurcation of volcanic plumes in a crosswind     

Gerald G. J. Ernst  John P. Davis  R. Stephen J. Sparks 《Bulletin of Volcanology》1994,56(3):159-169

Bent-over buoyant jets distorted by a crosscurrent develop a vortex pair structure and can bifurcate to produce two distinct lobes which diverge from one another downwind. The region downwind of the source between the lobes has relatively low proportions of discharged fluid. Factors invoked by previous workers to cause or enhance bifurcation include buoyancy, release of latent heat at the plume edge by evaporating water droplets, geometry and orientation of the source, and the encounter with a density interface on the rising path of the plume. We suggest that the pressure distribution around the vortex pair of a rising plume may initially trigger bifurcation. We also report new experimental observations confirming that bifurcation becomes stronger for stronger bent-over plumes, identifying that bifurcation can also occur for straight-edged plumes but gradually disappears for stronger plumes which form a gravity current at their final level and spread for a significant distance against the current. Observations from satellites and the ground are reviewed and confirm that volcanic plumes can show bifurcation and a large range of bifurcation angles. Many of the bifurcating plumes spread out at the tropopause level and suggest the tropopause may act on the plumes as a density interface enhancing bifurcation. Even for quite moderate bifurcation angles, the two plume lobes become rapidly separated downwind by distances of tens of kilometers. Such bifurcating plumes drifting apart can only result in bilobate tephra fall deposits. The tephra fall deposit from the 16 km elevation, SE spreading, bifurcating volcanic plume erupted on 15 May 1981 from Mt Pagan was sampled by previous workers and clearly displayed bilobate characteristics. Examples of bilobate tephra fall deposits are reviewed and their origin briefly discussed. Bilobate deposits are common and may result from many causes. Plume bifurcation should be considered one of the possible mechanisms which can account for come examples of bilobate tephra fall deposits.  相似文献   

频谱段图像及其应用的探讨     

叶泽田 《遥感学报》1993,(2)

本文描述了一种形成频谱段图像的方法,这种图像记录了相应地物的纹理信息。初步试验表明,在空间遥感中,这种频谱段图像是一种有用的数据源。  相似文献   

利用SPACE LAB彩色红外影像及数据复合技术对藏北牧草资源进行计算机分类的研究     

舒宁  关泽群 《遥感学报》1990,(1)

本文就在藏北草资源调查中,应用空间实验室量测摄影机(MC)摄得的彩色红外影像,及根据遥感影像目视判读所利用的信息空间特点和草场分类原理进行计算机自动分类的理论与方法,对利用辅助数据和影像数据复合技术的几种尝试进行了讨论,并依实地调查资料和专家判读结果对各种分类结果进行了评价。说明利用这种航天遥感资料,辅以Landsat影像生物量指标、DTM和坡度、坡向数据以及计算机自动分类技术,进行资源调查是可行的,可以达到最佳效果。  相似文献   

数字影像中角点与直线的高精度定位算子   总被引：8，自引：0，他引：8  

张剑清  张祖勋 《测绘学报》1994,23(2):98-106

本文在分析现有数定影像定位算子的基础上，提出了精确定位数字影像中角点与直线的高精度定位算子。这种算子通过精确定组成角点的两条直线，从而精确定位角点。实验表明，新的定位算子有很高的定位精度，在理想情况下，新定位算子的精度可达０．０２像素，最后，客种算子被用于数字影像的相对定向，取得了令人满意的结果。  相似文献   

Uniform half-plane elastodynamic problems by an approximate boundary element method     

Dionyssia-Pinelopi N. Kontoni  Dimitri E. Beskos 《Soil Dynamics and Earthquake Engineering》1987,6(4):227-238

In this paper the applicability of an approximate Boundary Element Method to uniform half-plane elastodynamic problems is investigated. This method employs the concept of images to construct approximate fundamental solutions for the half-plane and does not require any half-plane surface discretization. The method is formulated in the frequency domain for the case of harmonic disturbances or the Laplace transform domain for the case of transient disturbances. In the latter case a numerical inversion of the transformed solution is necessary to obtain the time domain response. The proposed method can be used as an alternative to boundary element methods that either utilize the infinite plane fundamental solution and thus require a half-plane surface discretization, or employ the exact half-plane fundamental solution, which even though leads to no surface discretization, is of a very lengthy and complicated form. Two characteristics numerical examples are used to illustrate the proposed method and study its advantages and disadvantages.  相似文献   

一种提高CCD成像卫星空间分辨率的方法研究   总被引：10，自引：0，他引：10  

周春平  田越  季统凯  吴胜利  张凤坡  许东  时春雨  姚勇航 《遥感学报》2002,6(3):179-182

从卫星硬件设计与地面软件处理相结合的角度出发，建立了一套提高卫星图像空间分辨率的方法。对模拟靶标图像、一航景物图像、遥感图像分别进行了不同分辨率成像效果的计算机模拟。结果表明，所建立的卫星图像空间分辨率提高理论是正确的，使卫星图像空间分辨率提高2倍甚至更多在理论上是可行的。这一研究成果的实际应用，将会提高卫星的空间分辨率，也可以在保持卫星分辨率的条件下，缩小光学仪器的焦距，使卫星相机小型化，减小其体积和重量。  相似文献   

虚拟现实技术在虚拟旅游中的应用   总被引：1，自引：0，他引：1  

徐素宁  韦中亚  杨景春 《地理与地理信息科学》2001,17(3):92-96

该文简要介绍了虚拟现实技术 ,通过对旅游电子商务的分析 ,讨论了虚拟旅游中的虚拟现实技术 ,提出基于WebGIS电子地图、全景图像生成和网络全景图像浏览组成的虚拟旅游系统技术方案 ,并展望了该项技术的广阔的市场前景  相似文献