Thursday, November 11, 2010

GIS:Geographical Information System

GIS
     
Introduction:
GIS means a Geographical Information System, it is  any information system which integrates hardware, software & data for capturing, storing, integrating, editing, analyzing, sharing, managing & displaying  geographic information for informing decision making or  data identified according to location. It consists of hardware and software that make it possible for digitized maps to be overlaid with data.
GIS allows us to view, understand, question, interpret and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports and charts.
GIS has some boundaries which may be jurisdictional, application oriented or purpose oriented for which specific GIS developed. Every GIS has its own boundaries.
These systems are used in remote sensing, navigation, localized search Engine, geography, emergency management, natural resources management etc.
GIS is used in emergency planner in the case of a natural disaster; asset management, location planning, warfare assessments, in criminology , remote sensing etc.
Data used in GIS is available in new formats, including digitized maps, machine-readable census data, and other machine readable data—including locally produced machine-readable statistics. 
There are applications of GIS which are tools that allows users to create queries, analysis spatial information, edit data, maps & present result of all operations.
GIS software represents features on the earth, such as buildings, cities, roads, rivers, and states, on a computer. People use GIS to visualize, question, analyze, and understand this data about the world and human activity .Often, this data is viewed on a map, which provides an advantage over using spreadsheets or databases.
The 1st GIS was developed by Dr. Roger Tomlinson named as Canada Geographic Information System (CGIS) which was 1st true operational GIS was used to store, analyse and manipulate data collected for the Canada Land Inventory (CLI). Since Dr. Roger Tomlinson has been known as “Father of GIS”.

Advantages & Applications:
Cities, streets, and rivers are not the only physical locations that can be mapped. GIS can be used to map dynamic events such as the path of a hurricane or the spread of a disease outbreak.
It helps the businesses to learn about their customers. E.g. A clothing Stores that target Youth can create maps showing where max. youth live so they can target their marketing activities to just those areas. It also helps business for better decision making, improved communication & accurate record keeping.
GIS makes map data interactive and, thus, more useful. For example, a GIS shows a street as more than a screen graphic—you can click on a GIS street map to find out the speed limit, the number of lanes, the last time it was paved, any planned construction, and a multitude of additional related facts. All this information provides an accurate understanding of the street. If a city needed to widen this street, it could use GIS to create a 50-foot buffer on the street to find the properties that fall within the buffer.
 GIS can then easily identify property owners affected by the project so that they may be contacted. GIS combines layers of data to find the best alternatives, saving invaluable time for a government or a company.
In many areas of business such as manufacturing and banking, organizations must meet government regulations regarding pollution and interstate trade. GIS provides tools to help companies comply with local, state, and national regulations.
These developments will, in turn, result in a much wider use of the technology throughout science, government, business, and industry, with applications including real estate, public health, crime mapping, national defense, sustainable development, natural resources, landscape architecture, archaeology, regional and community planning, transportation and logistics. GIS is also diverging into location-based services (LBS). LBS allows GPS enabled mobile devices to display their location in relation to fixed assets (nearest restaurant, gas station, fire hydrant), mobile assets (friends, children, police car) or to relay their position back to a central server for display or other processing.
A key difference between viewing map information on paper or mylar versus using a GIS is that each person using the GIS can create their own view of information. Each individual user can choose what to see, why to see it, how to see it, and how to use it. The content of any paper or mylar map can probably be converted (“digitized”) for use in the GIS.

GIS in Detail:
GIS use Space-Time as a key index variable for all other information in like RDBMS where text or numbers can relate many different tables using key index variables. This key is the location and/or extent in space-time. Generally variables used in GIS may be referred as date/time of occurrence and x, y and z coordinates representing longitude, latitude and elevation resp.
In modern GIS, method data creation is digitization, where a hard copy maps, survey, layouts or some other existing maps are transferred into a digital medium through the use of a computer- aided design (CAD) program, and geo-referencing capabilities.
GIS is system which consists of Data Representation, Data Capture, Projections, Coordinate Systems and registration, Data modelling, Networks, Map Overlays, Data Output.       

Components of GIS:

Software Of GIS:
          
This consists of -
1.      Graphical user interface for downloading and viewing GIS information including such simple interactions as magnification and measuring distances.
2.      A viewer for formulating queries and simple editing  including selection based on attributes or location, changing color and resolution; merging, labeling, and creating reports.
3.      An editor for data manipulation and editing  including layering.

Six Major GIS Software  Providers:
1.      Aotodesk – Offers Autodesk.
2.      ESRI – Offers Arclnfo/Arc view.
3.      Geographic Research Inc.- Offers simply Maps.
4.      Intergraphs- Offers Geomedia.
5.      Manifold System – Offers Manifold Enterprise Addition.
6.      Mapinfo – Offers Mapinfo.

GIS technology, as an expansion of cartographic science, has enhanced the efficiency and analytic power of traditional mapping. GIS technology is becoming an essential tool to understand the impacts of this change over time. GIS enables the combination of various sources of data with existing maps and up-to-date information from earth observation satellites along with the outputs of climate change models. This can help in understanding the effects of climate change on complex natural systems. One of the classic examples of this is the study of Arctic Ice Melting.
The outputs from a GIS in the form of maps combined with satellite imagery allow researchers to view their subjects in ways that literally never have been seen before. The images are also invaluable for conveying the effects of climate change to non-scientists.
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This article is the topic of unit "IT Trends" from Nagpur University syllabus MBA 3 rd Sem IT  notes.

Topics of this unit are is covered in other blog post. Links are given below.
  1. Biometrics
  2. Neural Network
  3. Google Earth
  4. Audio Visuals MPEG
  5. I-Pod
For more notes you can also refer to other links as given below 
 
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