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1.
CRAIG M. TROTTER 《International journal of geographical information science》2013,27(2):225-239
Abstract Remotely-sensed image data have long served as a primary source of information for. geographical information systems (GIS), with the transformation of data to information provided by visual image interpretation. Digital image data, in combination with recent advances in computer technology, currently allow visual image interpretation to be realised in a completely digital processing environment. However, it remains desirable to capitalize even further on the potential of digital image data for GIS, through the use of schemes involving automated data processing. The opportunities for, and impediments to, such schemes are considered here with particular reference to the provision of information for natural resource management. It is concluded that further—although foreseeable—developments in both research and technology will be required before fully operational procedures for the automated acquisition of GIS information from image data can be established. 相似文献
2.
R. F. TOMLINSON 《International journal of geographical information science》2013,27(3):203-218
Abstract Abstract This paper provides an overview of developments and applications of geographical information systems (GIS) in North America over the past 20 years, together with some indications of lessons learned and prospects for the future. Most developments in this field have been confined to a small number of sectors, including forestry, land registry, transport and facility planning, civil engineering, agriculture and environment, although progress has been variable. The wider use of GIS has been (and will probably continue to be) inhibited by a number of factors, such as lack of digital base mapping, limited digital data, unawareness among potential users and resistance to new technology, coverage of data, assessment of costs and benefits, technological developments affecting GIS and sources of funds for research to political structures, availability of skilled staff, lack of proper advice, the unwisdom of ‘going it alone’ and management problems (which are as important as technical problems, if not more so). A successful programme of GIS depends on a coordination of effort relating to applications, trained personnel, governmental involvement in R. &D. and development of a source of independent advice. 相似文献
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Paul Lewis Stewart Fotheringham Adam Winstanley 《International journal of geographical information science》2013,27(5):697-716
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. 相似文献
4.
G. GRAY TAPPAN DONALD G. MOORE WALTER I. KNAUSENBERGER 《International journal of geographical information science》2013,27(1):123-135
Abstract Development programmes in Sahelian Africa are beginning to use geographic information system (GIS) technology. One of the GIS and remote sensing programmes introduced to the region in the late 1980s was the use of seasonal vegetation maps made from satellite data to support grasshopper and locust control. Following serious outbreaks of these pests in 1987, the programme addressed a critical need, by national and international crop protection organizations, to monitor site-specific dynamic vegetation conditions associated with grasshopper and locust breeding. The primary products used in assessing vegetation conditions were vegetation index (greenness) image maps derived from National Oceanic and Atmospheric Administration satellite imagery. Vegetation index data were integrated in a GIS with digital cartographic data of individual Sahelian countries. These near-real-time image maps were used regularly in 10 countries for locating potential grasshopper and locust habitats. The programme to monitor vegetation conditions is currently being institutionalized in the Sahel. 相似文献
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Language plays a vital role in the communication, sharing and transmission of information among human beings. Geographical languages are essential for understanding, investigating, representing and propagating geo-spatial information. Geographical languages have developed and evolved gradually with improvements in science, technology and cognitive levels. Concerning the theoretical progress from geographical information ontology, epistemology and linguistic theory, this paper firstly puts forward the concept of a GIS language and discusses its basic characteristics according to changes in the structures, functions and characteristics of geographical languages. This GIS language can be regarded as a system of synthetic digital symbols. It is a comprehensive representation of geographical objects, phenomena and their spatial distributions and dynamic processes. This representation helps us generate a universal perception of geographical space using geographical scenarios or symbols with geometry, statuses, processes, spatio-temporal relationships, semantics and attributes. Furthermore, this paper states that the GIS language represents a new generation of geographical language due to its intrinsic characteristics, structures, functions and systematic content. Based on the aforementioned theoretical foundation, this paper illustrates the pivotal status and contributions of the GIS language from the perspective of geographical researchers. The language of GIS is a new geographical language designed for the current era, with features including spatio-temporal multi-dimension representation, interactive visualization, virtual geographical scenarios, multi-sensor perception and expedient broadcasting via the web. The GIS language is the highest-level geographical language developed to date, integrating semantic definitions, feature extraction, geographical dynamic representation and spatio-temporal factors and unifying the computation of geographical phenomena and objects. The GIS language possesses five important characteristics: abstraction, systematicness, strictness, precision and hierarchy. In summary, the GIS language provides a new means forpeople to recognize, understand and simulate entire geo-environments. Therefore, exploration of the GIS language’s functions in contemporary geographical developments is becoming increasingly important. Similarly, construction of the conceptual model and scientific systems of the GIS language will promote the development of the disciplines of geography and geographical information sciences. Therefore, this paper investigates the prospects of the GIS language from the perspectives of digital technology, geographical norms, geographical modeling and the disciplinary development of geography. 相似文献
6.
D. C. MASON D. G. CORR A. CROSS D. C. HOGG D. H. LAWRENCE M. PETROU 《International journal of geographical information science》2013,27(3):195-215
Abstract Remotely-sensed data constitute a major potential source of input to geographical information systems (GIS)However, these data often have a relatively poor classification accuracy compared with that of the cartographic data from maps with which they may be combined in the course of GIS analysis. The possibility exists of using data sets (in the form of digital maps) resident within a GIS in order to improve this accuracy, before the classified image is incorporated into the GIS. Results are discussed from a British Alvey Information Technology project to develop a system for the knowledge-based segmentation and classification of remotely-sensed terrain images, in which the knowledge contained in digital map 相似文献
7.
Peter F. Fisher 《International journal of geographical information science》2013,27(4):331-347
Abstract In most documentation of geographical information systems (GIS) it is very rare to find details of the algorithms used in the software, but alternative formulations of the same process may derive different results. In this research several alternatives in the design of viewshed algorithms are explored. Three major features of viewshed algorithms are examined: how elevations in the digital elevation model are inferred, how viewpoint and target are represented, and the mathematical formulation of the comparison. It is found that the second of these produces the greatest variability in the viewable area (up to 50 per cent over the mean viewable area), while the last gives the least. The same test data are run in a number of different GIS implementations of the viewshed operation, and smaller, but still considerable, variability in the viewable area is observed. The study highlights three issues: the need for standards and/or empirical benchmark datasets for GIS functions; the desirability of publication of algorithms used in GIS operations; and the fallacy of the binary representation of a complex GIS product such as the viewshed. 相似文献
8.
基于Web Geocoding的三维GIS快速定位方法研究 总被引：1，自引：0，他引：1
三维GIS技术已经逐渐发展成熟,其对客观世界的表达能给人以更真实的感受,然而三维GIS软件所需数据是海量的。由于遥感技术的发展,纹理数据的获取和处理已经变得容易和快速,而对于矢量数据的采集、存储是一个非常艰巨的工作,如何在短期内获取海量、精确的矢量地理信息数据,减少数据采集的费用和时间成了一大难题。通过基于网络的地理编码来查询获取矢量点状地理信息,将地理信息存储到本地数据库,并且将数据应用到系统中进行快速定位显示,实现地理位置的实时定位和查询,为各种专题三维GIS软件开发提供服务和扩展功能。 相似文献
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关于发展中国城市群GIS的探讨 总被引：4，自引：0，他引：4
城群GIS是适应城市群区域管治的需要,透过跨政府部门、跨行政区域的政府、企业、学术团体和公众之间的协作,共建和共享地理、人口、经济、资源等空间信息基础设施,发展多种多样的地理信息应用系统,服务于城市区域规划、环境保护、资源利用、大型基础设施建设、灾害防护方面的决策与行动。该文提出了城市群GIS概念,并探讨其功能和架构、关键技术、项目组织、系统实施问题,以期推动学术界对于跨组织、协作型城市群GIS的研究。 相似文献
10.
Language plays a vital role in the communication, sharing and transmission of information among human beings. Geographical languages are essential for understanding, investigating, representing and propagating geo-spatial information. Geographical languages have developed and evolved gradually with improvements in science, technology and cognitive levels. Concerning the theoretical progress from geographical information ontology, epistemology and linguistic theory, this paper firstly puts forward the concept of a GIS language and discusses its basic characteristics according to changes in the structures, functions and characteristics of geographical languages. This GIS language can be regarded as a system of synthetic digital symbols. It is a comprehensive representation of geographical objects, phenomena and their spatial distributions and dynamic processes. This representation helps us generate a universal perception of geographical space using geographical scenarios or symbols with geometry, statuses, processes, spatio-temporal relationships, semantics and attributes. Furthermore, this paper states that the GIS language represents a new generation of geographical language due to its intrinsic characteristics, structures, functions and systematic content. Based on the aforementioned theoretical foundation, this paper illustrates the pivotal status and contributions of the GIS language from the perspective of geographical researchers. The language of GIS is a new geographical language designed for the current era, with features including spatio-temporal multi-dimension representation, interactive visualization, virtual geographical scenarios, multi-sensor perception and expedient broadcasting via the web. The GIS language is the highest-level geographical language developed to date, integrating semantic definitions, feature extraction, geographical dynamic representation and spatio-temporal factors and unifying the computation of geographical phenomena and objects. The GIS language possesses five important characteristics: abstraction, systematicness, strictness, precision and hierarchy. In summary, the GIS language provides a new means for people to recognize, understand and simulate entire geo-environments. Therefore, exploration of the GIS language’s functions in contemporary geographical developments is becoming increasingly important. Similarly, construction of the conceptual model and scientific systems of the GIS language will promote the development of the disciplines of geography and geographical information sciences. Therefore, this paper investigates the prospects of the GIS language from the perspectives of digital technology, geographical norms, geographical modeling and the disciplinary development of geography. 相似文献
11.
数字地形模型数据产品特点 与评估分析 总被引：9，自引：2，他引：9
数字高程模型是支撑地理过程模型研究的重要基础数据。DEM数据获取、加工及压缩精度直接影响地学相关模型及地理过程的模拟效果和研究质量。在分析比较当今国际地学界应用DEM数据源的基础上，我们采用绝对差值法和三维剖面法对国家基础地理信息中心生产的基于1：50,000扫描地形图DEM产品(NFGIS_DEM)、GTOPO30_DEM数据及基于SRTM数据生产的DEM数据集进行了精度检验及评估。同时分析了影响由SRTM数据所生产的全球范围DEM数据集精度与数据质量。研究结果表明30-90m分辨率的SRTM_DEM产品在精度和数据质量控制方面远优于GTOPO30_DEM数据，与NFGIS_DEM数据质量相当。大范围乃至全球范围的30m分辨率SRTM_DEM产品，将极大促进基于DEM数据的地理过程模型的研究，尤其会大幅提升对DEM空间分辨率较敏感的地学相关研究能力。 相似文献
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GIS作为新一代地理学语言的特征 总被引：2，自引：1，他引：1
地理学语言是人类理解、研究、表达与传播地理信息的重要工具, 它随着人类科学技术的进步与认识水平的提高而不断演进。本文根据地理学语言在结构、功能及其特征方面所发生的变化, 结合地理信息本体论、认知论和语言学理论, 总结了GIS 语言的定义与基本属性, 阐述了GIS作为新一代地理学语言的本质特征、结构、功能以及内容体系, 明确了其在地理学研究中的地位与作用。GIS语言实现了地理对象的语义定义、特征抽象、行为表达和时空运算处理过程的高度统一, 是地理学语言的高级形态;通过分析GIS 语言所具有的抽象性、系统性、严密性、确切性、层次性等基本特征。认为GIS语言的概念与体系结构的形成, 将推动地理学及地理信息科学的发展。文中从数字技术的影响、学科范式的转变、发展导向和地理表达能力四个方面对GIS语言的研究作了展望。 相似文献
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Geospatial data and tools are key in locating lost or missing persons in as short a time as possible. In this study, we used a geographic information system (GIS) to analyze four years of search and rescue (SAR) mission data from Colorado to determine the appropriate use of GIS for volunteer-based SAR organizations with limited resources and GIS expertise. GIS can provide more sophisticated analyses of geospatial data than simple mapping technologies, but our findings indicated that complex spatial analysis might not be required on all missions, because the majority of missions were completed within six to ten hours. Instead, new technologies such as tablets with mapping software and online GIS systems that provide quick and easy access to up-to-date geospatial data such as imagery offer capabilities that could improve mission planning. Here we provide a framework in which SAR missions can apply geospatial technologies to aid with missions, identify critical “hotspots,” and enhance postanalysis and training. The work here is highly applicable for nonprofit SAR groups when deciding on what GIS technologies to consider for their areas. 相似文献
15.
中国山地垂直带的数字集成与基本规律分析 总被引：7，自引：2，他引：7
首次归纳出我国63类垂直带(包括31类基带)；在ArcGIS 8．3平台上,以山地垂直带谱“数字引擎”为内核,成功研制了“中国山地垂直带谱信息系统(1．0)”,将我国约239个山地垂直带谱进行了数字集成,使我们对我国垂直带谱数据的掌握从残缺上升为相对完备。该研究工作不仅为我国山地垂直带谱规律的数字分析提供了强大的手段,也为世界山地垂直带谱的数字集成提供了必要的理论和技术方法。还利用该系统,对重要垂直带界线如雪线、林线、高山草甸进行了空间规律分析。结果表明,除高山草甸经向变化缺乏明显规律外,其他垂直带界线的经、纬向变化的二次曲线(抛物线)模式比其他模式具有更高的相关系数。因而,抛物线模式应是我国山地垂直带宏观尺度上的基本空间模式。今后垂直带谱研究应在界线精度、带谱结构的地理学／生态学解释等方面继续深入。 相似文献
16.
Improving household accessibility to basic community services can help reduce poverty in upland areas. In this study, spatial analysis with GIS was used to measure the accessibility of different household income groups to community services in the landlocked upland municipality Claveria in Northern Mindanao, the Philippines. Important community services were identified through villagers' participation in a matrix‐scoring activity. Travel information was derived from key informant interviews while the geographical coordinates of sample households and important services were collected using GPS receivers. The Flowmap GIS software (version 7.2) was used to compute accessibility to services along the road network by habal‐habal (two‐wheel motorcycle). Outcomes from the participatory data gathering activities revealed that agricultural, educational and health facilities, as well as government services are important to the community to achieve sustainable livelihoods. Because local people perceive accessibility in terms of monetary costs, rather than distance, road distance measurements were converted into fare costs. Results of the accessibility analysis show that higher‐income household groups generally incur lower mean one‐way travel costs to reach important community services than poorer households. However, almost all households spend more than the daily per capita poverty threshold for the province to reach basic community services. A scenario to improve accessibility to services in the study area was investigated to emphasize the potential of GIS‐based accessibility analysis in rural service planning. 相似文献
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FANGJU WANG G. BRENT HALL SUBARYONO 《International journal of geographical information science》2013,27(3):261-283
Currently used methods for representing geographical information are inadequate because they do not tolerate imprecision. This leads to information loss and inaccuracy in analysis. Such expressive inadequacy is largely due to the underlying membership concept of classical set theory. To improve information processing in GIS research and application, an alternative membership concept is required. In this paper, we explore the inadequacy imposed upon geographical information representation by classical set theory and address the problems of information loss. A fuzzy relational data model is defined which is more representative for geographical information. A GIS database for agricultural land resource management is created by using the data model and a new technique for assessing land suitability is developed. The fuzzy representation largely facilitates data analysis in this GIS. The methods are tested with data from North Java, Indonesia using a vector-based GIS software package, Arc Info, and the analysis results are presented. 相似文献
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Isaac Karikari John Stillwell Corresponding author Steve Carver 《International journal of geographical information science》2013,27(3):343-362
The Government of Ghana is about to take steps under its Land Administration Project to initiate the adoption of geographical information systems (GIS) in the administration of land. This paper identifies some of the challenges for Ghana's leading lands agency, the Lands Commission Secretariat, and highlights problems such as the paucity of reliable data sets and lack of standards. One of the major planning issues in Accra is that of building encroachments, for which no digital information is currently available. The paper reports on a pilot study to record encroachments on public land and demonstrates the type of inconsistencies that are apparent between the planning and cadastral data sets that do exist. The paper emphasizes that appropriate applications of GIS in Ghana's land sector are those that consider the political, social and institutional contexts within which GIS is to be operationalized. 相似文献