1. INTRODUCTION TO GIS
GIS stands for Geographical Information System. It is defined as an integrated tool, capable of mapping, analyzing, manipulating and storing geographical data in order to provide solutions to real world problems and help in planning for the future.
Objectives of GIS
Some of the major objectives of GIS are to:
-Maximizing the efficiency of planning and decision making
-Integrating information from multiple sources
-Facilitating complex querying and analysis
-Eliminating redundant data and minimizing duplication
-Components of a GIS
A GIS has following components:
Hardware : It consists of the equipment's and support devices that are required to capture, store process and visualize the geographic information. These include computer with hard disk, digitizers, scanners, printers and plotters etc.
Software : The GIS software must have the basic capabilities of data input, storage, transformation, analysis and providing desired outputs. The interfaces could be different for different software's. ArcGIS by ESRI is the widely used proprietary GIS software. Others in the same category are MapInfo, Microstation, Geomedia etc. The development of open source GIS has provided us with freely available desktop GIS such as Quantum, uDIG, GRASS, MapWindow GIS etc., GIS softwares.
Data : The data is captured or collected from various sources (such as maps, field observations, photography, satellite imagery etc) and is processed for analysis and presentation.
Procedures : These include the methods or ways by which data has to be input in the system, retrieved, processed, transformed and presented.
People : This component of GIS includes all those individuals (such as programmer, database manager, GIS researcher etc.) who are making the GIS work, and also the individuals who are at the user end using the GIS services, applications and tools.
(Source IIT DELHI)