共查询到20条相似文献,搜索用时 15 毫秒
1.
none 《The Cartographic journal》2013,50(1):61-72
AbstractSome, but not all, branches of the tourist industry make heavy use of maps. The industry has discovered the marketing potential of the Internet but in many cases has not yet fully exploited the extra potential of web maps compared to the traditional paper maps. Web maps can up-to-date tourist information very well but they have to be carefully designed to take account of the limitations of the medium. To be most effective, web maps should be basically simple and convey sufficient information interactively, on request. The map and symbol design should convey intuitively where and how this interaction can take place. This paper summarizes the typical faults found in tourist web map design and provides suggestions on good design practice. 相似文献
2.
《制图学和地理信息科学》2013,40(1):15-30
This paper presents a model which combines three of the parameters of the "Swiss manner" of relief representation with the Yoeli method of analytical hill-shading. The model consists of various computational and graphic procedures that are intended to imitate by computer the complex hand-shading process. The first two procedures adjust the light source vertically and horizontally to the local relief forms. The adjustments avoid the disappearance of edges in unfavorable positions and exaggeration of others, and they utilize digitized data of the network of ridges and ravines. A third algorithm deals with "atmospheric perspective," the phenomenon of diminished value contrast in low lands and enhanced contrast in upper areas. This procedure also allows a general change in tonal value as a function of altitude. Other procedures deal with multicolor relief shading techniques, small-scale generalization, and selected reproduction problems. Graphic output has been performed on a modified printer (IBM 1443) and a CRT raster recorder. 相似文献
3.
《制图学和地理信息科学》2013,40(3):250-257
This paper reviews the recent development of web cartography based on Plewe's 2007 short paper in the U.S. National Report to the ICA, titled Web Cartography in the United States. By identifying major changes and recent research trends in web cartography, this paper provides an overview about what the web means to cartography, and suggests two major research directions for web cartography in the future: 1) the rise of user-centered design, including design of user interfaces, dynamic map content and mapping functions; 2) the release of the power of map-making to the public and amateur cartographers. I also present web cartography concepts in this paper to challenge the traditional research agenda in cartography. 相似文献
4.
Distribution of Large Volume Image Data Using the Mixed Mode of Java Servlet and COM on Web 总被引:1,自引:0,他引:1
WANGMi ZHUXinyan PANJun CHENNengcheng 《地球空间信息科学学报》2004,7(3):167-172
This paper reports some researches on distribution of large volume image data using techniques of the Mixed Mode of Java Servlet and COM on Web. The architecture and key technologies are discussed in detail. The web distribution system of image is implemented and the system is tested by the application instances. At last, the advantages and disadvantages for this web image distribution mode are analyzed. 相似文献
5.
This paper reports some researches on distribution of large volume image data using techniques of the Mixed Mode of Java Servlet and COM on Web. The architecture and key technologies are discussed in detail. The web distribution system of image is implemented and the system is tested by the application instances. At last, the advantages and disadvantages for this web image distribution mode are analyzed. 相似文献
6.
《制图学和地理信息科学》2013,40(4):175-186
Understanding the spatial dimension of fear of crime in the urban environment is important to understanding behaviors in response to this concern. Making this connection between perception and action has long been a goal of scholars in the social and health sciences, though this complex relationship has yet to be fully elucidated. Specifically, in studies on fear of crime and its influence on behavior, a variety of definitions and methods have been employed. This situation has yielded insights, as well as inconsistencies. In the past decade, Geographic Information Systems (GIS) has been added to this methodological mix, though it too has contributed limited understanding of the environmental perception-behavior nexus. During this time, some scholars have integrated a traditional technique for accessing environmental perception, the sketch map, with this newer technology. This article provides a review and critical assessment of the way GIS has been used to understand fear of crime, specifically through the integration of sketch maps. This focus is framed by an overview of substantive and methodological concerns and concludes with a discussion of continued research needs. As behavioral responses to fear of crime are acknowledged to impact physical and mental health and overall well-being, in addition to the viability of neighborhoods, research in this area will continue apace. However, for integration of sketch maps in GIS to be a valuable methodological contributor to this line of inquiry, users of the approach must understand its complexities. This article outlines these issues so that they may be considered in future research and may improve the ability for this approach to yield new understanding of fear of crime. 相似文献
7.
Web环境下房产测绘信息三维可视化技术研究 总被引:1,自引:0,他引:1
Web环境下的三维可视化技术存在诸多技术难点。相对单机及局域网环境,Web环境下的网络响应时间将很大程度上影响着三维可视化的实际效果。文章围绕这一问题,从三维建模效率和三维模型数据量两方面入手,在分析现有方法不足的基础上,结合房产测绘信息特点,提出了基于模型库的房产测绘信息三维场景实时构建方法、基于模块化和参考复用的三维建模方法,进而提出一套行之有效的解决方案,使Web环境下房产测绘信息三维可视化技术得以实用化。实验系统证明了该方法的有效性、实用性。 相似文献
8.
9.
Completeness and classification correctness of features on topographic maps: An analysis of the estonian basic map
下载免费PDF全文
![点击此处可从《Transactions in GIS》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In an increasingly GIS‐literate world, the availability of quality topographic maps and map databases is critical for the numerous users of spatial data. Particularly governmental agencies, first responders, and utility and transportation services, rely on the completeness and classification correctness of these maps. Estonia has systematically updated its topographic Basic Map in digital form over the past 15 years. An analysis of the Estonian production process in the period 2003‐2006 provides a useful case study of both error types and error frequencies encountered in topographic mapping. Errors of completeness and classification correctness of topographic features are analyzed at two levels of specificity: in general, across all map sheets, and in detail according to the field‐workers who performed the mapping. The structure of errors at the two levels was different by geometry and error types; however, both systematic and individual errors were evident. The systematic errors indicated a need for revision and improvement of the data capture specifications, which was accomplished. The individual errors were addressed by additional training for the field‐workers involved. 相似文献
10.
本文重点介绍平面平行大气多次散射方程的求解及Tovs资料与图像的配准等问题。对于散射方程的求解本文吸取了众多的研究成果,但由于我们已知的是大气顶的辐射,而未知的是地表反射率,因此直接利用正演方法将存在问题。为此,本文引进地面总波谱辐射与直接波谱辐射的比值作为中间变量,并提出了一种有效的解决办法。本文将重点介绍程序设计,并对一些结果进行了讨论,指出了进一步的工作。经过一年多的试运行,证明该软件运行可靠,时效较高,已达到常规运行的要求。 相似文献
11.
大气影响是遥感定量化应用的主要障碍之一。本文首先分析了大气对遥感图像产生的各种影响并对影响程度进行了一般的阐述,然后在原理和方法上对典型的大气影响校正算法进行了总结。通过分析我们认为,为了校正遥感图像所受到的大气影响,定量地获取当时当地的大气条件是完成这一工作的必要条件,而且是非常重要的条件之一。为此,我们提出了利用NOAA星载垂直探测器资料即TOVS资料,结合使用气溶胶模型,通过大气辐射传输模型,建立地面辐射量与卫星测量值之间的关系,并完成了对NOAA-AVHRR图像的大气影响校正。在此基础上对我们的模型和算法进行了详细论述。这一模型是一套适用于发展业务软件的校正模型,软件发展完善后将为NOAA-AVHRR数据的定量化应用打下基础。 相似文献
12.
地表植被覆盖度遥感估算及其气候效应研究进展 总被引:1,自引:0,他引:1
赵健赟 《测绘与空间地理信息》2015,(8)
FVC是研究表植被覆盖的重要参数,其估算精度直接影响生态、环境变化研究结论的科学性。本文通过研究用于FVC计算的遥感数据,以及统计模型、混合像元分解、数据挖掘等估算方法和植被覆盖变化气候效应,指出大数据时代背景下融合海量、多平台、多时空、多尺度数据的FVC估算是必然趋势,其方法不仅具有高精度、高可靠性等特点,而且将向智能化、自动化的方向发展,植被覆盖变化气候效应研究将逐步定量化,地气作用过程和机理将成为其重要的研究方向。 相似文献
13.
Terrain reversal effect (TRE) causes reversed 3D shape perception in satellite images and shaded relief maps (SRMs), and introduces difficulties in identifying landforms such as valleys and ridges. With this paper, in a controlled laboratory experiment, we compare how well 27 participants could identify valleys and ridges over 33 locations using SRMs, color satellite images and grayscale satellite images. The main depth cue is shadow both in vertical-view images and SRMs. However, the presence of texture and color in images also affect 3D shape perception. All our participants experience the illusion strongly: with the SRMs, it is very severe (2% accuracy), with grayscale images low but considerably better than SRMs (17.6% accuracy), and slightly worse with color imagery (15.3% accuracy). These differences between SRMs and imagery suggest that the participants who are able to bypass the illusion consciously or subconsciously interpret the photographic information. We support this observation further with a cue-strength analysis. Furthermore, we provide exploratory analyses of the effects of expertise, global convexity bias, and bistable perception. Our original empirical observations serve towards a better understanding of this visual illusion, and contribute towards nuanced and appropriate solutions to correcting for TRE differently for satellite images and SRMs. 相似文献
14.
15.
Lauren Patterson Marie Urban Aaron Myers Budhendra Bhaduri Eddie Bright Phillip Coleman 《Transactions in GIS》2009,13(2):215-228
LandScan USA is a 90 m population distribution model that is used for a variety of applications, including emergency management. Models should have a measure of accuracy; however, the accuracy of population distribution models is difficult to determine due to the inclusion of multiple input datasets and the lack of quantifiable, observable (validated) data to confirm model output. Validated data enables quantification of: (1) overall model accuracy and (2) changes in model output at different levels of quality control. This article examines the effect of quality control for two national school datasets incorporated as input in LandScan USA for Philadelphia County, Pennsylvania; which had a local, validated school dataset available. The effect of each stage of quality control efforts utilized throughout the LandScan USA process were assessed to determine what level of quality control was required to have a statistically significant change of the model's population distribution. The typical level of quality control for LandScan USA resulted in 36% of schools being moved to the correct location and 20% of missing student enrollments were found, compared to 87% and 98% respectively for the validated dataset. The costs of increasing quality control resulted in a six-fold increase in labor time; however, the additional quality control did not produce statistically significant improvements in the LandScan USA model. Thus, typical quality control efforts for schools in LandScan USA produced a population distribution similar to the validated level of quality control, and can be applied with confidence for policy, planning, and emergency situations. 相似文献
16.
硬化地表增加是城市发展的重要特征之一。应用SPOT遥感影像提取了地表硬化度指数,拟合了地表硬化度和多光谱因子间的关系(Rspot=0.818,p0.001),并以北京市建成区为例进行了硬化地表格局特征研究。结果表明,北京市城区中等和高密度建设用地占绝对优势,高密度或较高密度建设覆盖格局的异质特征主导了北京市中心的总体景观格局。另外,尺度效应研究发现,在高度城市化的大都市,与较高分辨率影像相比,中等分辨率影像提取的地表硬化度精度更高,应用不同分辨率遥感信息提取的硬化地表格局特征有明显差异。 相似文献
17.
利用泰森多边形和格网平滑的人口密度空间化研究——以徐州市为例 总被引:2,自引:0,他引:2
在运用泰森多边形作边界替代得到徐州市区人口密度的分布图后,采用GCAWI法实现了徐州市区人口数据的空间化,提出了采用大小两种格网错置的平滑方法,并运用此方法得到徐州市2000年和2005年的500 m×500 m的格网人口密度分布图。结果表明:①通过对比两个年份的人口密度分布图可以发现,徐州市区人口密度在2000年~2005年期间具有南移东扩的趋势;②利用大小两种格网错置平滑的方法实现了对人口密度空间化与平滑两个功能,平滑后的结果表明,徐州市区人口密度的空间分布具有块状集聚、轴状延伸的格局,整体来看呈现出"大"字形的态势;③通过与直接运用核函数内插得到的人口密度分布图的对比可以发现,前者对反映人口密度分布的细部差异比较敏感,而后者仅能反映出人口密度空间分布的整体格局。 相似文献
18.
水库作为水利设施的重要组成部分,在蓄水、供水、防洪、泄洪等方面起着极为重要的作用。计算水库面积,对于水库的蓄水量,影响的流域范围等有着重要的参考价值。本文以石梁河水库为例,选取了较为常见的利用GIS技术和遥感技术计算水库面积的方法,并科学地比较了两种方法的优缺点,为选择水库面积计算方法提供有力依据。 相似文献
19.
建立地震灾害损失评估数据库是以ILWIS和PCARC/INFOGIS软件为工作平台。它能支持矢量格式的专题图件、栅格形成的遥感数据及关系表中的属性数据;它还可以实现矢量-栅格转换;而且数据库中的属性数据作为一个独立的关系表格存贮,并对应于其相关的空间单元。该数据库是以1976年唐山地震的航空遥感资料为基础,主要分3步进行。第一:建立地震区的基础地理数据库,包括:地理坐标、河流水系、县级行政区、公路、铁路和居民点;第二:应用航空遥感数据(航空影象)进行震区建筑物倒毁、生命线工程破坏及场地震害的分类分级,建立地震灾害数据库;第三:在GIS支持下,生成高烈度区包络线,并进行地震灾害据失评估。 相似文献
20.
基于NDVI和LSMM的干旱区植被信息提取研究——以新疆吐鲁番市为例 总被引:1,自引:0,他引:1
植被是干旱区生态建设重要的组成部分,而植被覆盖度是生态环境变化的重要指示,是评价生态系统健康的前提条件。本文在遥感等技术的支持下,以landsatTM影像为数据源,选用归一化植被指数(NDVI)和线性光谱混合分析模型(LSMM)两种方法进行分析比较,提取吐鲁番市近20年植被覆盖度,并对该地区植被覆盖度的演变特征进行分析。结果表明:①LSMM方法能较好地提取干旱区植被信息,指标简单且分类精度较高。②NDVI方法提取植被时,受到很多限制,在干旱区不宜采用。 相似文献