共查询到20条相似文献,搜索用时 15 毫秒
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针对传统SIFT匹配方法用于嫦娥三号降落影像匹配效率低的问题,提出了一种改进的降落影像序列特征匹配方法。重构了着陆器垂直降落阶段拍摄过程的几何模型,并得到了不同降落影像中的同名匹配点之间的几何约束关系,然后通过SIFT方法进行影像中极值点的提取和特征描述,最终将几何模型约束用于极值点的匹配点搜索过程中,优化了匹配过程。采用嫦娥三号着陆器真实降落影像进行了试验,结果表明,改进方法能够取得较为稳定的匹配结果,且平均可以减少约为18%的匹配耗时,研究结果对后续深空探测任务的开展具有重要的参考价值。 相似文献
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Spatial data conflation involves the matching and merging of counterpart features in multiple datasets. It has applications in practical spatial analysis in a variety of fields. Conceptually, the feature‐matching problem can be viewed as an optimization problem of seeking a match plan that minimizes the total discrepancy between datasets. In this article, we propose a powerful yet efficient optimization model for feature matching based on the classic network flow problem in operations research. We begin with a review of the existing optimization‐based methods and point out limitations of current models. We then demonstrate how to utilize the structure of the network‐flow model to approach the feature‐matching problem, as well as the important factors for designing optimization‐based conflation models. The proposed model can be solved by general linear programming solvers or network flow solvers. Due to the network flow formulation we adopt, the proposed model can be solved in polynomial time. Computational experiments show that the proposed model significantly outperforms existing optimization‐based conflation models. We conclude with a summary of findings and point out directions of future research. 相似文献
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针对传统的遥感影像数据库中影像特征匹配效率低下的问题,该文提出一种基于多尺度模型的数据库影像特征匹配方法。为遥感影像数据库构建多尺度模型,能较高效率地在数据库中快速定位候选的匹配影像;基于搜索得到的候选影像,采用快速排序算法逐层筛选最佳匹配影像,从而实现了数据库匹配影像的精确定位。实验结果表明:所提算法不仅能高效地完成影像间特征点匹配运算,还能从数据库中精确地筛选得到最佳的匹配影像;且随着数据库中影像总数的增加,该方法的优势表现得更加明显。这一研究将为遥感影像数据库的高效、实时及动态匹配提供可能性。 相似文献
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提出一种基于结构自适应特征的城区宽基线影像特征点匹配方法。首先,对影像提取点特征和直线特征,挖掘点特征与其邻域内直线特征之间的几何关系,构建结构自适应的特征区域和特征描述符,并通过双向匹配策略获得初始匹配结果。然后,基于初匹配结果估计影像基础矩阵,构建核线约束的结构自适应特征匹配算法进行二次匹配。最后,将已匹配特征作为控制基础设计匹配扩展算法,进一步增加匹配点数量。本文方法以特征点邻域几何结构为出发点,构建自适应的特征区域,能够在显著的影像视角变化下,为同名特征点提取影像内容一致的特征区域,进而获得相似的特征描述符。试验结果证明,与传统算法相比,本文方法在城区宽基线影像上能够同时获得更多的正确匹配特征和更高的匹配正确率。 相似文献
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The automatic selection of railway marshaling lines is an important procedure in the generalization of road network data. The line selection results must be geometrically consistent with the topological features of the external/internal structural and topological connectivity of the railway stations. When current methods are used to process the lines at railway marshaling stations, which exhibit crisscrossing, dense, non‐hierarchical, and complex characteristics, the selected lines tend to be topologically and structurally erroneous. In this article, we propose an automated method for the selection and generalization of complex railway lines that accounts for multiple feature constraints. First, we identify four types of line structures in accordance with the spatial and topological features of railway stations. Then, based on length and spacing thresholds specified for the generalization process, line selection is performed while accounting for constraints regarding structural robustness and topological extensibility. Finally, we report the validation of our method on a dataset relating to Chengdu Railway Station, China. The results indicate that our method successfully preserves the external and internal structural features and connectivity of railway stations. 相似文献
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针对复杂场景中的遥感影像道路提取问题,论文提出了一种多特征约束的影像道路提取方法,并开展了论文方法可行性论证。该方法首先,根据道路宽度的先验知识以及道路的几何特征,提出一种改进的线段二次提取模型,利用线段长度和道路宽度确定候选道路种子点集;其次,输入道路结构信息,基于道路辐射特征对候选道路种子点进行整体匹配评价;再次,当候选道路种子无法符合辐射特征要求时,提出一种浅色机动车检测模型,以此将浅色机动车结果作为道路上下文特征,利用道路上下文特征对候选道路种子点进行分析;然后,构建道路拓扑分析模型,依据道路拓扑特征对候选道路种子点进行最终验证;最后,对提取道路种子点进行优化处理,并提出道路跟踪及拟合方法。通过不同复杂场景、不同分辨率高分辨率遥感影像下开展的不同方法实验结果对比分析表明,相对于其他商用软件ECognition和Erdas的方法,本方法自动化程度更高,运行效率高,适用于解决道路类型多样化、几何光谱噪声大的复杂场景道路提取问题。 相似文献
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In the field of surveying, mapping and geodesy, there have been a number of works on the error-in-variable (EIV) model with constraints, where equality constraints are imposed on the parameter vector. However, in some cases, these constraints may be inequalities. The EIV model with inequality constraints has not been fully investigated. Therefore, this paper presents an inequality-constrained total least squares (ICTLS) solution for the EIV model with inequality constraints (denoted as ICEIV). Employing the proposed ICTLS method, the ICEIV problem is first converted into an equality-constrained problem by distinguishing the active constraints through exhaustive searching, and it is then resolved employing the method of equality-constrained total least squares (ECTLS). The applicability and feasibility of the proposed method is illustrated in two examples. 相似文献
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An integrated urban systems model with GIS 总被引:3,自引:0,他引:3
The main purpose of this paper is to explore a possible integration for the entire transportation modeling procedure – from
data inventory to future demand forecasting – by implementing integrated land use and transportation models with a geographic
information system (GIS). In order to make an integrated, procedural modeling system possible, Land Use and Transportation
modeling system with GIS (LUTGIS) has been developed and presented in this paper.
There are four sub-systems in LUTGIS: (1) a data inventory system, (2) a traffic analysis zone generation system, (3) an
integrated land use and transportation modeling system, and (4) a graphic user interface (GUI) system. Since the main target
of this paper is to explore a possible way to create a viable system, LUTGIS integrates currently available and user-friendly
computing technologies. For both transportation planners and administrative decision-makers, such an operable system is very
desirable for sharing information so they may arrive at a consensus through the use of LUTGIS, an integrated land use and
transportation modeling system.
Received: 22 October 1998/Accepted 11 July 1999 相似文献
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GPS Solutions - We evaluate the performance of Galileo broadcast NeQuick model by comparing it with GPS broadcast Klobuchar and the original NeQuick2 models. The broadcast coefficients of Galileo... 相似文献
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When certain constraints in the kinematic state parameters of a multi-sensor navigation system exist, they should be taken
into account for the improvement of the positioning accuracy and reliability. In this paper, two types of robust estimators
for integrated and two stages of Kalman filtering with state parameter constraints are derived based on the generalized maximum
likelihood Lagrangian condition, respectively. The properties of the two estimators are discussed. The changes of the state
estimates and their covariance matrices as well as the residual vector caused by the constraints are derived and analyzed.
It is shown by a simulated example that the precision of the state estimates provided by the Kalman filtering with constraints
is better than that provided by the Kalman filtering without considering the state parameter constraints; and the robust Kalman
filtering with constraints further improves the reliability and robustness of the state estimates. 相似文献
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Weighted total least-squares with constraints: a universal formula for geodetic symmetrical transformations 总被引:4,自引:2,他引:2
Xing Fang 《Journal of Geodesy》2015,89(5):459-469