地理视频数据模型及其应用开发研究

讨论地理视频的基本概念和数据模型,尝试提出地理视频数据的实体-关系图,并在网络环境中进行地理视频应用开发.地理视频数据模型的核心要素是:对视频帧进行位置和语义描述,建立视频片段的轨迹图层和元数据,并在轨迹图层中扩充视频帧线性参照.通过空间参照、线性参照和语义参照将视频数据与地理数据集成,实现地理视频的查询、检索、播放和地图跟踪.以河南大学校园和开封市公路网络为例,采集地理视频数据,建立地理视频数据库,发布网络地图和视频服务,并分别采用最新的Adobe Flex框架、ArcGIS Server ADF和JavaScript Mashup方式,开发网络视频GIS应用系统.原型系统开发表明,地理视频数据模型适用于网络视频GIS开发,且在技术实现上较为简单.     

地理立体视频数据分析与模型设计

针对当前GIS中视频数据管理的功能较单一、检索方法单调的现状,通过分析、整合空间数据、视频数据,设计了一个地理立体视频数据模型(GeoSVDM),它包括视频、空间几何、专题属性、语义标注以及线性参照等要素,基于面向对象方法,抽象了视频帧及其位置、视域、视频片段及其轨迹等组件对象及其逻辑关系,并应用UML定义了模型结构。该模型通过建立视频对象与地理实体间的空间位置参照及语义参照关系,支持可视化、检索以及量测等多个应用功能,实现了地理立体视频对象数据组织与检索表达。试验表明,GeoSVDM具有功能丰富、集成化以及松耦合、灵活可扩展等优点,适合于地理立体视频的管理,并为GIS中应用可定位媒体提供了基础数据模型。     

基于视频的地理场景增强表达研究

视频具有表达直观、信息丰富、动态实时等特点,将其与GIS有机集成形成地理视频(GeoVideo),可更加形象的表达地理空间.该文利用视频分割技术将视频分割为具有不同摄像机运动状态的视频片段,针对摄像机运动的视频片段,采用摄像机跟踪(Camera Tracking)技术求算视频帧对应的摄像机内外参数,并基于地理视频数据模型,采用KML/XML描述视频帧、摄像机位置、摄像机姿态等之间的时空映射关系.最后,设计了原型系统,在网络环境中聚合地理信息服务、视频流媒体服务与KML文档服务等,实现了视频与三维地理场景的交互与融合.实验表明,基于该地理视频数据模型,利用视频数据可实现对地理场景的增强表达,使用户能更形象的认知地理空间.     

基于移动定位的行为数据采集与地理应用研究

微观个体行为的研究是人文地理学者解释人文地理现象的重要视角,而个体时空数据的获取是制约行为研究的重要瓶颈之一。随着手机的普及,移动定位服务为个体时空数据的获取提供了新的技术手段。通过与人口普查、交通调查等传统移动性数据获取方法的比较,基于移动定位的时空行为数据所具有特点包括:(1)采集个体位置和移动信息真实;(2)定位精度高、信号覆盖广;(3)可持续实时动态获取移动信息;(4)可减少行为数据编码过程的信息损失,适合大规模采集。详细介绍了基于移动通信网络和手机终端的移动定位技术原理,并通过微观个体行为分析和宏观城市动态空间规划的两个典型案例,实证基于移动定位的时空行为数据在城市规划等领域的可行性和适用性。移动定位方法显示出了巨大的技术优势和应用前景,但一些重要的基础性问题仍没有解决,特别是个人的隐私保护和移动定位的地理尺度问题。现有的研究成果表明,基于移动定位数据的地理应用仍处在试验和探索阶段,新的数据获取协议、数据分析方法、地理时空模式提取方法等研究亟待展开。     

广东省县级地名管理系统与地名数据库的建立

一、目标为了实现地名管理工作的现代化,通过计算机建立地名数据库管理系统势在必行。目前主要有单纯的地名属性数据库管理系统。但他没有地名空间位置与图形支持,无法采用可视化技术。地名是地理空间信息的重要组成部分,建立地名数据库和管理系统,应该实现地名属性信息与空间信息统一的目标。在做法上,为了避免建立地形空间数据库所造成的数字化工作量大、时间长、经费高的缺点。采用在扫描地形图或数字正摄影像图上建立矢量地名层,对地名直接进行空间定位,同时在ＧＩＳ平台与数据库上建立地名空间数据库和属性数据库,实现了扫描图…     

位置感知计算中定位信息的自然语言描述

讨论位置感知计算中定位信息表达存在的不足,引入自然语言描述作为补充,介绍自然语言中的空间概念,并分析了影响空间定位信息向自然语言转换的因素,归纳为尺度依赖、方向依赖和身份依赖,讨论制约因素影响下的参考框架、参考点和方位词的选择,并以地图作为空间转化媒介,给出一组人们日常使用的定位描述句式,最后以车辆监控系统和图书馆导航为测试平台,针对室外和室内两种不同应用环境进行了自然语言描述实验.     

车辆GPS监控数据的自适应采集算法研究

在大规模GPS车辆监控中,当精度要求高时终端与中心端的通信负荷及中心端的数据处理负荷都很大,自适应采集技术可以有效解决这一问题。该文提出了车辆GPS监控数据的自适应采集算法,采用基于端点速度约束和里程约束的拟合多项式表达速度函数,综合考虑终端有地图和无地图的情况,采用偏差距离表示速度的方向偏差,并提出了数据的恢复算法、算法评价指标以及算法的应用模式。最后基于北京市的真实路网和实测GPS数据对算法进行了验证,恢复后的数据在速度和位置上都逼近真实数据,数据压缩率达3%,证明了算法的有效性。     

基于道路网格索引的无线通信基站定位与实现

为了促使无线通信基站定位技术进一步用于解决用户定位信息与空间地图信息匹配的问题,该文提出了一种基于话单的道路定位算法:针对移动场景,在基站定位过程中结合话单定位参数信息和空间道路信息,实现了将用户直接定位到道路上的目标;对矢量道路进行解析并采用网格索引技术建立索引,设计过滤条件对算法进行优化,提高了定位的求解速度。以实际话单进行测试,得到了合适的网格化步长参数,通过对定位精度进行分析,证明了该算法的可行性和有效性。该算法可进一步提高基站定位技术的应用范围,对5G及物联网技术也将有重要意义。     

可定位媒体库构建及其在影像解译中的辅助应用

随着多媒体技术与GPS定位技术集成应用日益增多,可定位媒体已经成为一种表达与传递地理空间信息的重要数据源。针对这些结构繁杂、数量庞大、多源异构的可定位媒体数据,本研究提出了一种基于Multi Point的视频管理模型,使用SQL Server 2008空间数据库构建可定位媒体库,同时基于多级网格构建空间索引,实现可定位媒体快速检索,并将其应用于遥感标志选取与遥感分类核查中,通过照片、视频与遥感影像同步播放,快速标注与显示于遥感影像中,可增强遥感影像局部地理场景的真实表达,降低解译人员对地理空间的认知难度,提高遥感影像解译的效率,从而在影像解译与质量控制方面起到辅助作用。     

GPS车辆位置服务平台的设计与研究

0引言随着企事业的迅速发展,运输车辆增加、车辆管理的问题状况日益突出,然而,由于受到距离的限制,车辆却无法得到充分的监控,因此司机偷工,公车私用等问题时有发生,给企事业管理带来了极大的不便。利用先进的G PS定位技术和成熟的移动通信技术以及强大的数据库技术等,对车辆进行实时动态信息采集,并根据对这些信息的综合处理结果,对车辆进行实时     

Big Data from the Ground Up: Mobile Maps and Geographic Knowledge

Consumer users of maps on mobile devices are producing noteworthy geographic knowledges in the contexts of their own lives that are distinct from those of professional data scientists. By leveraging the streaming nature of big data in mobile maps and zooming multiscalar views, consumer users' mobile map practices produce a popular, multiscalar form of visual geographic knowledge that is both enabled and limited by its big data assemblage and associated technologies. The first half of this article outlines the role of consumer user practices amidst spatial big data assemblages, not for volunteered geographic information or aggregate analysis but for contextual, everyday use. Consumer users and their knowledges are coconstituted through mobile map viewing and as materially limited technological practices. This article focuses specifically on the consumer users' concept of scale in this context, for Web-based maps' multiscalar views differentiate them from older maps. The second half analyzes mobile map consumer users' concepts of scale in a series of focus groups that involved both questions and observing participants' actions with maps on their own phones. Instead of passively accepting maps at predetermined optimized scales from the map application, consumer users actively viewed the map across scales while searching but not while navigating.     

面向对象整体GIS数据模型的设计与实现

本文在前期GIS概念数据模型研究的基础上 ,提出了面向对象整体GIS数据模型 ,并针对整体GIS软件的实现在系统数据组织、存储结构与访问机制方面进行了较为深入的探讨 ,Deskpro最后简单介绍了基于整体GIS数据模型的商品化软件———SuperMapDeskpro的实现情况     

Spatial video and GIS

GIS elemental unit representations of spatial data are often defined in terms of points, lines and areas. However, another type of spatial data that is becoming frequently captured, but as yet is largely ignored in GIS, is that of video. While digital video recording is a commonly encountered medium in modern society and encompasses many forms, from simple personal camcorders through to sophisticated survey and surveillance systems, its geographical representation in a GIS has not been fully examined or realised. In the majority of cases the video footage is usually captured while the device and/or the objects being viewed are in motion. What is of particular interest is when video streams can be, or have been, associated with spatial data such as location and orientation to create geographically referenced videographic data, which, for simplicity, will be defined as spatial video. Fundamentally, the nature of video is to record space, so when spatial properties can be accurately acquired and associated with this footage, an important geographical element can be considered for integration and analysis within a GIS.

Existing spatial video systems, both commercial and research, are predominantly used in survey or LBS roles and are usually bespoke and application specific. These systems do not model spatial video to any recognised standards that is generalised to be both data and platform independent. They do not support GIS integration and/or analysis from a purely spatial content perspective. A video-image/remote-sensing centric approach prevails where usage options range from simple visualisation interfaces to interactive computer vision systems. What has been largely overlooked is a spatial approach where the inherent geographical extent recorded in each video frame can be modelled and used in a geo-spatial analysis context. While this modelling approach has not been fully realised, it does exist in a GIS form based on Open Geospatial Consortium standards, where the spatial context of video is defined in a structure called a ViewCone. However, a ViewCone only defines a 2D model of the geographical extent of each frame and is restricted to a three-or-five sided polygon representation.

Thus, this article examines the potential of modelling spatial video through the use of elemental data types within GIS; gives some examples of using this approach; describes some problems in using spatial video within GIS; and then demonstrates how these problems are being solved. This is done in three stages: Firstly, a detailed overview of spatial video in its current GIS role is provided – this is achieved through a complete introduction to the distinct elements of spatial video followed by a review of its use in both commercial and academic application areas. Secondly, a brief theoretical overview of an alternative GIS-constrained ViewCone data structure is given that defines a more flexible spatial video model for both 2D and 3D GIS analysis and visualisation. Thirdly, a selective sample of results is presented based on an implementation of this approach being applied to a constrained spatial video data source in a specific study area.     

Pedestrian network map generation approaches and recommendation

With the advanced capabilities of mobile devices and the success of car navigation systems, interest in pedestrian navigation systems is on the rise. A critical component of any navigation system is a map database, which represents a network (e.g., road networks for car navigation) and supports key functionality such as map display, geocoding, and routing. Road networks, mainly due to the popularity of car navigation systems, are well defined and publicly available. However, in pedestrian navigation systems, as well as other applications including urban planning and physical activity studies, road networks do not adequately represent the paths that pedestrians usually travel. Currently, there is a void in literatures discussing the challenges, methods, and best practices for pedestrian network map generation. This coupled with the increased demand for pedestrian networks is the prime motivation for development of new approaches and algorithms to automatically generating pedestrian networks. Three approaches, network buffering, using existing road networks, collaborative mapping, using Global Positioning System (GPS) traces collected by volunteers, and image processing, using high-resolution satellite and laser imageries, were implemented and evaluated with a pedestrian network baseline as a ground truth. The results of the experiments indicate that these three approaches, while differing in complexity and outcome, are viable for automatic pedestrian network map generation. The recommendation of a suitable approach for generating pedestrian networks for a given set of sources and requirements is provided.     

A Manifesto on Mobile Computing in Geographic Education*

Mobile, location‐aware computing technology is widely available. In this article we sketch out a manifesto on mobile computing in geographic education (MoGeo) for consideration and debate within the geographic community. At the core of our argument is the idea that emerging mobile computing technologies will allow teachers to bring the classroom and pedagogic materials into the field, and that the resulting in situ educational experience will enhance learning by contextualizing the complex and abstract concepts that we teach. We provide a set of key principles that can guide the development of field experiences for students using these new technologies.     

A Manifesto on Mobile Computing in Geographic Education*

Abstract

Mobile, location-aware computing technology is widely available. In this article we sketch out a manifesto on mobile computing in geographic education (MoGeo) for consideration and debate within the geographic community. At the core of our argument is the idea that emerging mobile computing technologies will allow teachers to bring the classroom and pedagogic materials into the field, and that the resulting in situ educational experience will enhance learning by contextualizing the complex and abstract concepts that we teach. We provide a set of key principles that can guide the development of field experiences for students using these new technologies.     

A less‐is‐more approach to geovisualization – enhancing knowledge construction across multidisciplinary teams

The ‘less‐is‐more’ concept in interface design for computer applications has recently gained ground. In this article, the concept is adopted for a user‐centered design of geovisualization application. The premise is that using simple and clear design can lead to successful applications with improved ease of use. Over the last three decades, the development of GIS and geovisualization has seen a marked increase in the levels of interaction between the user, the system and the information. However, these enthusiastic advances in technology have not resulted in a significant increase in the number of users.

This article suggests that types of user interaction should not simply emphasize traditional GIS functions such as zooming and panning but move towards interaction based on facilitating the knowledge construction process. Considerations are made for the complexity of the system, the task at hand and the skills and limitations of the users. These elements are particularly important when maps act as the mediators in collaboration with users across disciplinary backgrounds. In such cases, the emphasis on simplicity and usability becomes as important as functionality. In these situations a geovisualization application designed for specific uses can maximize effective development of geographic knowledge.

In this article, a minimalistic design approach to geovisualization is adopted by creating a geographic profiling tool which shifts the emphasis from technological advances or interaction with the map to the interaction elements key to building the spatial knowledge of GIS experts and non‐experts alike. To evaluate this notion of ‘less‐is‐more geovisualization’ the profiling tool is evaluated according to usability matrices: efficiency, effectiveness and learnability. How well the Suburban Profiler contributes to these elements is assessed by conducting a video analysis of the types and forms of user interaction available. The video analysis demonstrates the usefulness and usability of the Suburban Profiler, providing proof of concept for ‘less‐is‐more geovisualization’.     

基于GIS制作遥感影像地图的研究与实践

遥感与地理信息系统一体化是科学技术发展的趋势,遥感影像地图是现代地图发展的新图型。本文介绍了基于CITYSTAR进行遥感影像地图编制的研究和实践,阐述了其工艺过程和关键技术,并以厦门和达竹两个例子说明具体的工作方法与步骤。     

城市空间框架数据研究

该文基于地理空间概念和地理信息数字化表达与共享的特点,探讨了框架数据的作用、确定原则,推导出城市空间框架数据体系,即建立城市直接空间参照体系和间接空间参照体系。后者中,基于地块的多尺度无缝不规则网格是整合城市社会经济数据的关键,也是当前城市空间数据基础设施框架数据体系建设中的薄弱环节。