Web GIS

Web GIS

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  Web-based GIS andvirtual globes Zhaoying Wei 1. Definition and explanation of Web-based GIS Web-based GIS refers to the use of the World Wide Web as a means of disseminating and processing geographic information, and presenting the result. [1] This technique democratizes GIS. Maps and spatial analysis results can be published and viewed by the readers on the Web. With its development, not only data are shared, information-processing functions are also shared and distributed over the Internet. A virtual globe, a product of Web-based GIS, is a 3D software model or representation of the earth or another world. [2] A virtual globe provides the users with the ability to freely move around in the virtual environment by changing the viewing angle and position. Virtual globes have the additional capability of representing many different views on the surface of the Earth. These views may be of geographical features, man-made features such as roads and buildings, or abstract representations of demographic quantities such as population. 2. Overview and history of Web-based GIS The history of Web-based GIS can be traced back to the development of the Xerox Map Viewer in 1994 (Putz 1994). The Xerox Map Viewer used a Web Browser via HTML format and Common Gateway Interface (CGI) programs to provide interactive mapping functions via the Internet. The technical framework of
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  the Map Viewerwas followed by many early on-line GIServices applications. [3] Another important research project was the Alexandria Digital Library Project (Buttenfield and Goodchild 1996; Frew et al. 1998), which explored comprehensive services for online spatial queries, map browsing, and metadata indexing. Besides the development of academic research, the GIS industry is also developing several software packages to provide online mapping functions, such as ESRI’s ArcIMS (Internet Map Server), INTERGRAPH’s GeoMedia Web Map, AutoDesk’s MapGuide, and GE SmallWorld’s Internet Application Server. In early 2005, the combination of two new technologies, Asynchronous JavaScript and XML (AJAX) and image tiling improved the performance of Web-based GIS significantly. Until these advancements, the limitations of traditional Web-based GIS applications were in the size of image data and client/server communication. AJAX and image tiling allowed retrieving only the data needed by user’s request to the web server. So the total amount of images or data interchanged between the client browser and web server decreased significantly. AJAX also made it realized that the user’s interaction with the application can happen asynchronously. [maps.search.ch] and [maps.google.com] are the two early examples of Web-based GIS applications which adopt both AJAX and tiling techniques together. [4] With the development of Web-based GIS, a new and evolving geospatial web emerged. Multiple virtual globes such as Google Earth and NASA's World Wind, have emerged and are positioned to proceed as the gateway to the geospatial Web. On November 20, 1997, Microsoft released a popular offline virtual globe in
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  the form ofEncarta Virtual Globe 98, followed by Cosmi’s 3D World Atlas in 1999. The first widely publicized online virtual globes were NASA World Wind (released in mid-2004) and Google Earth (mid-2005). The latest 3D Virtual Globe release in 2011 is 3rd Planet. According to different purposes, the design of virtual globes varies considerably. 3. The importance of Web-based GIS and virtual globes in advancing science and discovering knowledge In recent years, most popular GIS applications are referred to as Web-based GIS applications (Milosavljević et al, 2005). Web-based GIS applications are used by most users because most of them while working with spatial data need only to review the data. Nowadays, Web-based GIS applications have thick clients that implement a large part of the functionality. These solutions are based on the usage of data from various sources and their combining, querying, processing, displaying and changing. [5] Virtual globes are rapidly becoming an easy and accessible way of finding, distributing and visualizing all sorts of data in a geographical context. The amazing thing about virtual globes not only lies in the excellent visualization, but also in the capabilities which allow you fly along in three-dimensions. [6] Another important feature of virtual globes is that various scientific data can be displayed overlaying multiple satellite images. People can even add and edit various applications beyond the original functions of virtual globes if it is an Open-source Project, such as World Wind and Google Earth. 4. An example of how Web-based GIS may affect daily life
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  The improvements ofWeb-based GIS attract more people to start to use it and have transformed the way people live, work, and behave. Take a simple example of finding a hotel close to a particular resort. Thanks to Web-based GIS, the cost and labor associate with the query can be reduced. I don’t need to find data for the road networks, and separate data for hotel locations, and purchase a complete GIS software program that is capable of conducting a network analysis with the shortest path-finding function. Furthermore the next time I want to plan other trips, the old data may not be valid as road network and hotel information may have already changed. In a Web-based environment, however, I only need to search for Web sites that provide these kinds of services. Since the Internet services link the data with the data sources, the data are always up to date. Web- based GIS would allow users to be more productive in applying Web-based GIS technologies in actual application rather than spending valuable time in operating the software and collecting the data. The emergence of virtual globes further extends the revolution of GIS techniques. For example, real-time weather information can now be displayed in Google Earth alongside the landmarks and routes in which the general public are interested. People can use Google Earth to search: “Can I have enough time to arrive home before the rain if I take this route?” “Is the tornado near my house?” 5. My idea and speculation Web-based GIS still has great potential to benefit our daily life. For example, the visualization and analysis of data helps us when we shop for a home. We can access the data of crime rate, unemployment rate, and type of business nearby
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  etc. in aneighborhood using services offered online. With the combination of all these data we can effectively evaluate the neighborhood. We can also mark and share favourite antique shops or delicious restaurants with our friends. Web- based GIS could also dramatically improve the efficiency of exploring quantitative data for companies. For example, if one can simultaneously visualize the data and the predictions from models, the areas where the data agree or disagree with the model will jump out. Furthermore, by incorporating time series images, we can easily compare human behavior in different time intervals. For instance, we want to compare the number of consumers in one particular shopping mall in day and night on weekends so users can choose a better time for him or her to shop to avoid waiting a long time when checking out. With web-based GIS and virtual globe, everyone can make their own customized geographical applications.
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  References: [1]. Zhong-Ren Peng,Ming-hsiang Tsou. 2003. Internet GIS: distributed geographic information services for the Internet And Wireless Networks. [2]. Wikipedia. 2012. <http://en.wikipedia.org/wiki/Virtual_globe>. [3]. Yoon-Seop Chang. 2006. XML Web Service-based development model for Internet GIS applications. International Journal of Geographical information Science, Volume 20, Issue 4, 2006 [4]. Ming-hsiang Tsou. 2005. Recent development in Internet GIS. GISdevelopment.net. [5]. The web-wide world. 2006. Nature. Vol 439, 16 February 2006. [6]. Suzana Dragice. 2004. The potential of Web-based GIS. Jornal of Geographic Systems, Volume 6, Number 2, 79-91, DOI: 10.1007/s10109-004-0133-4