Fedora 12: Constantine

Wednesday, April 30, 2008

Geographical Information System - GIS

Although many GIS have been successfully implemented, it has become quite clear that two-dimensional maps with most complex contours and color schema cannot precisely present multidimensional and dynamic spatial phenomena. Most GISs in use today have not been designed to support multimedia data and therefore have very limited capability due to the large data volumes, very rich semantics and very different modeling and processing requirements.


Introduction

Geographical Information Systems (GIS) are computer-based systems that enable users to collect, store, process, analyze and present spatial data.

It provides an electronic representation of information, called spatial data, about the Earth’s natural and man-made features. A GIS references these real-world spatial data elements to a coordinate system. These features can be separated into different layers. A GIS system stores each category of information in a separate "layer" for ease of maintenance, analysis, and visualization. For example, layers can represent terrain characteristics, census data, demographics information, environmental and ecological data, roads, land use, river drainage and flood plains, and rare wildlife habitats. Different applications create and use different layers. A GIS can also store attribute data, which is descriptive information of the map features. This attribute information is placed in a database separate from the graphics data but is linked to them. A GIS allows the examination of both spatial and attribute data at the same time. Also, a GIS lets users search the attribute data and relate it to the spatial data. Therefore, a GIS can combine geographic and other types of data to generate maps and reports, enabling users to collect, manage, and interpret location-based information in a planned and systematic way. In short, a GIS can be defined as a computer system capable of assembling, storing, manipulating, and displaying geographically referenced information.

GIS systems are dynamic and permit rapid updating, analysis, and display. They use data from many diverse sources such as satellite imagery, aerial photos, maps, ground surveys, and global positioning systems (GPS).

Multimedia and Geographical Information System (GIS)

Multimedia

Multimedia is a technology that encompasses various types of data and presents them in an integrated form. There are several types of data that are used by the technology, including text, graphics, hyperlinks, images, sound, digital and analogue video and animation.

Although many GIS have been successfully implemented, it has become quite clear that two-dimensional maps cannot precisely present multidimensional and dynamic spatial phenomena. Moreover, there is a growing need towards accessing spatial data. It seems that merging GIS and Multimedia is a way to deal with these issues.

The latest advances in computer industry especially in hardware have led to the development of the Multimedia and Geographical Information System (GIS) technologies. Multimedia provides communications using text, graphics, animation, and video. Multimedia GIS systems is a way to overcome the limitations displayed by the technologies when they are used separately. Multimedia can extend GIS capabilities of presenting geographic and other information. The combination of several media often results in a powerful and richer presentation of information and ideas to stimulate interest and enhance information retention. They can also make GIS more friendly and easier to use. On the other hand, multimedia can benefit from GIS by gaining an environment which facilitates the use and analysis of spatial data. The result is a system, which has the advantages of both worlds without retaining most of their disadvantages.


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