A User‐centered Design for the Addition of Interactive Masking Capability within an existing Web GIS

This article presents a case study of how a user‐centered design (UCD) approach was utilized during the addition of interactive masking capability to an existing web‐based geographic information system (Web GIS). By analyzing and discussing specific aspects of the user‐developer dialog within the context of a Web GIS software development life cycle, this article presents a case study for similar systems. The results of the UCD methodology is a discussion that presents a shift from an initial design to a new design that, based on user feedback, furthers the utility and usability of interactive masking within the Web GIS.     

电子地图导航技术框架研究

导航技术在用户使用电子地图中起着重要的引导作用,本文在拓宽地图学和地理信息工程领域中将电子地图导航技术分为了6类:显示设备、信息重构、缩放+漫游、概览+细节、焦点+上下文和基于提示的对象可视化技术,并构建了电子地图导航技术框架研究的漏斗模型,并对框架中的地理任务分类、导航技术分类、导航技术理论、可用性研究和评估方法以及最后方案的复用5个方面进行了阐述,并提出了初步的解决方案。     

What about people in pedestrian navigation?

Pedestrian navigation has become an important theoretical and practical research topic in many disciplines such as cartography, geographical information science, global and indoor positioning, spatial behavior, psychology, sociology, and neuroscience. Many research studies view pedestrian navigation using process-oriented and goal-directed approaches. However, this paper revisits people’s needs in pedestrian navigation and classifies their needs as three layers: physical sense layer, physiological safety layer, and mental satisfaction layer according to Maslow’s theory. This paper introduces a people-centric framework for pedestrian navigation theory based on these three layers and discusses theoretical challenges for meeting each layer of people’s needs. These challenging theories may represent promising and valuable research and promote usage of pedestrian navigation systems or devices in the future.     

绝对空间定位到相对空间感知的行人导航研究趋势

相对空间比绝对空间更易于被人理解。行人导航本质是以相对于人的导航环境视觉与空间等相对语义来动态引导行人的过程,即相对导航。目前,GIS导航理论以绝对定位与空间建模为基础,没有充分理解人对相对语义的认知差异,缺乏基于相对语义的导航理论模型。首先,总结了以绝对空间定位与表达为基础的行人导航研究,提出了相对空间感知的行人导航研究新方向。然后,剖析了相对导航研究的理论研究需求,如:行人相对导航数据采集与建模、行人导航环境相对语义的提取、行人导航行为的自动感知分析、行人导航的多感官交互机制、行人导航路径选择与确认机制等。最后,展望了未来行人导航研究与重要创新的3个阶段。     

有限状态自动机辅助的行人导航状态匹配算法

行人导航状态的自动识别是行人导航研究的一个难点问题,对提升行人导航软件服务的精准反馈与改善导航性能至关重要,此方面已有的研究工作很少。本文提出了一种基于有限状态自动机的行人导航状态匹配算法,其核心思想是在识别行人动作基础上匹配行人当前导航状态。利用谷歌眼镜及智能手机采集的多种传感器数据对行人动作进行识别,得到其动作特征参数;然后将行人导航状态分为熟悉、陌生及迷路3类,根据有限状态自动机理论建立状态转移模型,设计基于该模型的行人导航状态匹配算法;最后,实现状态匹配算法,通过试验对该算法的有效性进行验证。试验结果表明,该算法能够较好地识别行人导航过程中的状态转移,其中对熟悉向陌生状态转移识别准确度较高,对迷路状态识别准确度达到90%。     

Exploring differences of visual attention in pedestrian navigation when using 2D maps and 3D geo-browsers

ABSTRACT

Despite the now-ubiquitous two-dimensional (2D) electronic maps, three-dimensional (3D) globe viewers, or 3D geo-browsers such as Google Earth and NASA World Wind have gained much attention. However, the effect of such interactive 3D geo-browsers on spatial knowledge acquisition and decision-making is not well known. This study aims to explore the potential benefits of using interactive 3D geo-browsers in three processes of pedestrian navigation (self-localization, spatial knowledge acquisition, and decision-making) in digital environments. We employed eye tracking to show differences of visual attention in pedestrian navigation between a 2D map (Google Map) and a 3D geo-browser (Google Earth). The results indicated that benefits and drawbacks of 3D representations are task dependent. Participants using the 3D geo-browser had an extensively visual search resulting in significantly longer response time than the 2D participants for spatial knowledge acquisition, whereas 3D users performed a more efficient visual search and resulted in a better navigation performance at complex decision points. We speculate that the inefficient knowledge acquisition when using the 3D geo-browser was most probably due to information overload and obstructed views. Landmarks in photorealistic 3D models assisted recall of spatial knowledge from mental maps, which contributed to efficient decision-making at a complex turning point. These empirical results can be helpful to improve the usability of pedestrian navigation systems.     

基于众源数据的室内外一体化行人路网构建

行人路网的完整性和准确性是保障步行导航服务的关键。当前的行人路网大多是基于室外道路设施构建的,缺乏室内可步行路径的数据支持,无法在导航应用中提供准确、真实的最优路径规划服务。鉴于此,本文提出了一种基于众源数据的室内外一体化行人路网构建方法,采用智能手机定位传感器与惯性传感器记录的众源轨迹,首先对缺失或者漂移的室内步行数据进行筛选,然后使用改进的行人航位推算(PDR)方法推算出准确的室内轨迹,进而采用莫尔斯理论生成涵盖室内外行人路径的完整行人路网。试验分析中对搜集到的260条步行轨迹数据进行行人路网构建,并使用高精度测量设备采集真实路网数据进行对比分析,结合OSM数据对试验结果进行综合评价。试验结果表明,本文方法能够准确、完整地生成室内外一体化行人路网。     

顾及地标可视性的室内导航路径优化算法

提出了一种构建室内行人通行网络的方法,利用矢量建筑图自动构建室内建筑、地标的可视关系,建立行人导航通行规则,支持室内导航路径规划。实验结果表明,此方法能够有效描述室内行人通行规则,并满足拓扑网络构建的实时性需求,减少大规模存储与维护室内路网的压力。在此基础上提出了一种多目标导航路径优化算法,该算法时间开销较低,能够实时地进行路径规划,得到的最优路径与最短路径相比具有更高的地标可见性和覆盖率。     

Spatial Knowledge Acquisition with Mobile Maps,Augmented Reality and Voice in the Context of GPS-based Pedestrian Navigation: Results from a Field Test

GPS-based pedestrian navigation systems have become increasingly popular. Different interface technologies can be used to communicate/convey route directions to pedestrians. This paper aims to empirically study the influence of different interface technologies on spatial knowledge acquisition in the context of GPS-based pedestrian navigation. A field experiment was implemented to address this concern. Firstly, the suitability of the evaluation methods in assessing spatial knowledge acquisition was analyzed empirically (focusing on the ability of differentiating “familiar” and “unfamiliar” participants). The suitable methods were then used to compare the influence of mobile maps, augmented reality, and voice on spatial learning. The field test showed that in terms of spatial knowledge acquisition, the three interface technologies led to comparable results, which were not significantly different from each other. The results bring some challenging issues for consideration when designing mobile pedestrian navigation systems.     

Integrating Indoor and Outdoor Spaces for Pedestrian Navigation Guidance: A Review

In light of the many improvements within 3D urban modeling and Location‐Based Services, this article provides a timely review of the state‐of‐the‐art on integrating indoor and outdoor spaces in pedestrian navigation guidance aids. With people moving seamlessly between buildings and surrounding areas, navigation guidance tools should extend from merely outdoor or indoor guidance, to provide support in the combined indoor‐outdoor context. This article first examines the challenges and complexities of integrating indoor and outdoor spaces into a single navigation system. Next, by using objective selection criteria, 36 relevant studies were withheld and further reviewed on their specific developments in data model requirements, and algorithmic and context support for integrated IO navigation systems. This review shows that the challenges of dealing with both indoor and outdoor space structures, while taking into account pedestrian's freer use of space, currently complicate the proposition of a unified IO space concept for navigation. However, there are some ongoing developments (e.g. context definitions, algorithmic extensions, increased data availability, growing awareness of pedestrians’ perception during wayfinding) that will help to bring outdoor and indoor spaces closer together in the realm of combined geospatial analysis.     

基于众源轨迹数据的行人路网提取

目前,导航位置服务应用提供的路线大多基于机动车道路网数据,难以满足行人导航的需求,有无完备的行人道路网络成为制约行人导航应用的重要因素,因此,本文提出了一种基于莫尔斯理论的行人路网提取方法。首先对轨迹进行预处理,清除轨迹数据中的冗余和噪声,并对原始轨迹进行合理分割,形成清晰的轨迹集合;然后利用莫尔斯理论,对步行轨迹密度图中的“山脊线”进行提取,并重构步行道路网。试验分析时采用深圳大学校园步行GPS轨迹数据进行行人路网提取,通过将提取的行人路网结果与OpenStreetMap（OSM）数据进行定性和定量比较,验证本文方法的有效性;同时通过与当前典型的路网提取方法进行对比分析发现,本文方法能提取出高质量的行人路网。     

国外卫星导航系统星间链路发展研究

利用星间链路提升卫星导航系统性能已成为全球卫星导航系统的重要发展趋势之一。以GPS为代表的国外卫星导航系统都在积极发展星间链路。我国北斗卫星导航系统也将在新一代全球导航卫星上搭载星间链路,目前已开展在轨试验。通过国内外文献查阅和跟踪研究,系统梳理比较了GPS,GLONASS和Galileo三大全球系统已投入使用和正在论证的星间链路技术方案。在此基础上归纳了星间链路的发展特点与趋势:1)星间链路的设计不再局限于实现自主导航,更倾向于通过星地联合实现增强提升导航性能;2)星间链路的发展当前以高频段射频星间链路为主,激光星间链路是未来的发展方向;3)星间链路测距通信将主要采用时分多址体制。相关研究成果对我国北斗卫星导航系统星间链路的发展具有借鉴意义。     

卫星导航可用性监测技术

随着全球卫星导航系统（GNSS）的不断完善和在各领域的不断推广运用,导航系统的重要性日益增大,导航系统是否可用,直接影响到用户的体验甚至用户的安全.本文论述了卫星导航系统可用性监测相关技术,主要从卫星系统完好性监测、电离层闪烁监测技术和电磁环境监测三个方面分别进行论述.      

EGNOS系统进展情况

EGNOS是欧洲建设的第一个卫星导航系统，它通过增强两个军用导航系统来向系统服务区内提供差分改正数据和系统完好性信息，来满足高安全用户的需求。本文全面介绍了欧洲EGNOS系统总体设计、技术亮点、系统体系结构、工程现状、系统性能以及系统开发和走向等有关方面的最新情况，为我们国家建设自己的卫星导航增强系统积累经验。     

Augmentation of Indoor Positioning Systems with a Barometric Pressure Sensor for Direct Altitude Determination in a Multi-storey Building

To determine the correct floor of a user in a multi-storey building using pedestrian navigation and guidance services is a challenging task, as most common indoor location techniques provide only 2D position determination. Consequently, it is recommended to augment the position determination system with a barometric pressure sensor for direct observation of height differences. In the research project NAVIO (Pedestrian Navigation Systems in Combined Indoor/Outdoor Environments), tests with a barometric pressure sensor have been performed and their results are presented in this paper. The tests show that using a barometric pressure sensor, the building floor at which a person is located can be determined with the standard deviation of better than ± 0.5 m.     

A new evil waveforms evaluating method for new BDS navigation signals

With the advent of new global navigation satellite systems (GNSSs) and new signals, GNSS users will rely more on them to obtain higher-accuracy positioning. Evil waveform monitoring and assessment are of great importance for GNSS to achieve its positioning, velocity, and timing service with high accuracy. However, the advent of new navigation signals introduces the necessity to extend the traditional analyzing techniques already accepted for binary phase-shift keying modulation to new techniques. First, the well-known second-order step thread model adopted by the International Civil Aviation Organization is introduced. Then the extended new general thread models are developed for the new binary offset carrier modulated signals. However, no research has been done on navigation signal waveform symmetry yet. Simulation results showed that, waveform asymmetry may also cause tracking errors, range biases, and position errors in GNSS receivers. It is thus imperative that the asymmetry be quantified to enable the design of appropriate error budgets and mitigation strategies for various application fields. A novel evil waveform analysis method, called waveform rising and falling edge symmetry (WRaFES) method, is proposed. Based on this WRaFES method, the correlation metrics are provided to detect asymmetric correlation peaks distorted by received signal asymmetry. Then the statistical properties of the proposed methods are analyzed, and a proper deformation detection threshold is calculated. Finally, both simulation results and experimentally measured results of Beidou navigation satellite system (BDS) M1-S B1Cd signal are given, which show the effectiveness and robustness of the proposed thread models.     

地学信息可视化系统的可用性辅助评估工具设计研究

针对传统可用性评估方法中存在的主要问题,提出要设计地学信息可视化系统的可用性辅助评估工具。本文首先分析传统常用的可用性评估方法及其存在的主要不足,提出解决这些问题的基本想法。然后提出地学信息可视化系统可用性辅助评估工具的总体设计思路及系统的工作流程,并详细阐述了系统的功能模块与关键技术实现。该工具可以减少测试过程中的主观影响,节省开支,更加有效地利用有限的样本,提高可用性评估结果的科学性。     

Geospatial Information Integration for Authoritative and Crowd Sourced Road Vector Data

This article describes results from a research project undertaken to explore the technical issues associated with integrating unstructured crowd sourced data with authoritative national mapping data. The ultimate objective is to develop methodologies to ensure the feature enrichment of authoritative data, using crowd sourced data. Users increasingly find that they wish to use data from both kinds of geographic data sources. Different techniques and methodologies can be developed to solve this problem. In our previous research, a position map matching algorithm was developed for integrating authoritative and crowd sourced road vector data, and showed promising results ( Anand et al. 2010 ). However, especially when integrating different forms of data at the feature level, these techniques are often time consuming and are more computationally intensive than other techniques available. To tackle these problems, this project aims at developing a methodology for automated conflict resolution, linking and merging of geographical information from disparate authoritative and crowd‐sourced data sources. This article describes research undertaken by the authors on the design, implementation, and evaluation of algorithms and procedures for producing a coherent ontology from disparate geospatial data sources. To integrate road vector data from disparate sources, the method presented in this article first converts input data sets to ontologies, and then merges these ontologies into a new ontology. This new ontology is then checked and modified to ensure that it is consistent. The developed methodology can deal with topological and geometry inconsistency and provide more flexibility for geospatial information merging.     

GPS／BDS／GLONASS组合伪距单点定位性能测试与分析

本文以高山峡谷地区以及城市建筑群区域GNSS卫星受山体及建筑物遮挡的实际问题为出发点,通过选取不同的卫星方位角模拟不同遮挡环境,研究GPS／BDS、GPS／GLONAS和GPS／BDS／GLONASS组合系统伪距单点定位模型对于单GPS、单BDS系统在不同遮挡环境下的定位精度和三维导航可用性等方面的改善情况。结果表明,组合系统相对于单系统,增加了可见卫星数,降低了PDOP值,当观测条件不佳时,可以很好地改善定位精度和提高三维导航可用性。