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171.
Improvements in communication and processing technologies have opened the doors to exploit on-board cameras to compute objects’ spatial attitude using only the visual information from sequences of remote sensed images. The strategies and the algorithmic approach used to extract such information affect the estimation accuracy of the three-axis orientation of the object.This work presents a method for analyzing the most relevant error sources, including numerical ones, possible drift effects and their influence on the overall accuracy, referring to vision-based approaches. The method in particular focuses on the analysis of the image registration algorithm, carried out through on-purpose simulations. The overall accuracy has been assessed on a challenging case study, for which accuracy represents the fundamental requirement. In particular, attitude determination has been analyzed for small satellites, by comparing theoretical findings to metric results from simulations on realistic ground-truth data. Significant laboratory experiments, using a numerical control unit, have further confirmed the outcome.We believe that our analysis approach, as well as our findings in terms of error characterization, can be useful at proof-of-concept design and planning levels, since they emphasize the main sources of error for visual based approaches employed for satellite attitude estimation. Nevertheless, the approach we present is also of general interest for all the affine applicative domains which require an accurate estimation of three-dimensional orientation parameters (i.e., robotics, airborne stabilization). 相似文献
172.
针对UDDI、CSW、Clearinghouse等空间信息服务注册与查找方式存在的不足,提出了空间信息服务管理机制,集成实现空间信息服务的搜索、描述、分类、组织、存储、发布、发现为一体的空间信息服务管理架构。基于此,实现了空间信息服务描述与注册、服务发现与调用等服务活动过程,为空间信息服务共享与增值应用奠定基础。 相似文献
173.
三维激光扫描技术是近年来发展起来的一门新技术,其在众多领域中有非常广阔的应用前景。本文介绍了三维激光扫描仪目前的应用现状,以及原理和数据后处理方法。最后通过青海玉树山体建模实例叙述了Riegl VZ-400扫描仪如何获取数据、点云数据的拼接及三维模型的建立。 相似文献
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This paper investigates the synergistic use of high-resolution multispectral imagery and Light Detection and Ranging (LiDAR) data for object-based classification of urban area. The main contribution of this paper is the development of a semi-automated object-based and rule-based classification method. In the implemented approach, the diverse knowledge about land use/land cover classes are transformed into a set of specialized rules. Further, this paper explores supervised Gaussian Mixture Models for classification, which have been primarily used for unsupervised classification. The work is carried out on test data from two different sites. Contribution of the LiDAR data resulted in a significant improvement of overall Kappa. Accuracy assessment carried out for aforementioned classification methods shows higher overall kappa for both the study sites. 相似文献
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Acquisition and registration of terrestrial 3D laser scans is a fundamental task in mapping and modeling of cities in three dimensions. To automate this task marker-free registration methods are required. Based on the existence of skyline features, this paper proposes a novel method. The skyline features are extracted from panoramic 3D scans and encoded as strings enabling the use of string matching for merging the scans. Initial results of the proposed method in the old city center of Bremen are pre-sented. 相似文献
180.
利用地面激光扫描仪具有的数据获取速度快、精度高、实时性强、能全天候工作等优点,在快速获取三维点云的基础上,通过点云自动拼接、Hausdorff距离检测不同时期建筑物的三维模型变化,并改进了检测算法,提高了算法的执行效率。通过拟合平面构建Delaunay三角网求解变化区域的面积来评估灾害对建筑物的破坏程度,从而为灾害应急响应以及保险理赔等提供了可靠的决策依据。 相似文献