GEOGRAPHIC INFORMATION SYSTEM DEVELOPED BY :POONAM SHARMA
Geographic Information System
WHAT IS GIS ?
GIS is a set of computerized tools for collecting, storing, retrieving, transforming and displaying spatial data.
A particular form of Information system applied to geographical data.
A system is a group of connected entities and activities which interact for a common purpose.
What is Not GIS ? GPS : Global Positioning System A static map : paper or digital Maps are often a “ product ” of GIS
A way to visualize the analysis
How do we create Geographic Information ? Aerial Photography Land Surveying GPS What Where Geographic Information Fields Samples Population Census Administrative Records
Why is GIS Important ? GIS technology is to geographical analysis what the microscope, the telescope,and computers have been to other sciences. It integrates spatial information within a single system.
It allows us to manipulate and display geographical knowledge in new and exciting ways.
Why is GIS so HOT ? GIS gives a “ high tech ” feel to geographic information. Cont…
Maps are fascinating and so are maps in computers.
There is increasing interest in geography and geographic education.
GIS is an important tool in understanding and managing the environment .
Disciplines & Technologies GIS is a convergence of technological fields and
GIS has been called an “ Enabling Technology ”.
Geography Broadly concerned with understanding the world Long tradition in spatial analysis.
Provides techniques for conducting spatial analysis.
Cartography Computer cartography provides methods for digital It is concerned with the display of Spatial Information.
It provides long tradition in the design of maps which is an important form of output from GIS.
Remote Sensing Remote Sensing includes techniques for data acquisition and processing anywhere on the globe Images from space and the air are major source of Interpreted data from a remote sensing system can
be merged with other data layers in a GIS
Photogrammetry Photogrammetry is the source of most data used for
In Photogrammetry we use aerial photography for making measurements.
Statistics Statistics is important in understanding issues of error and uncertainty in GIS data. Many models are built using GIS are statistical in nature.
Many statistical techniques are used for analysis.
Computer Science CAD provides software, techniques for data input, display and visualization. Advances in computer graphics provide hardware, software for handling and displaying graphic objects.
DBMS contribute procedures for system design and handling large volume of data.
GIS as a set of Interrelated Subsystem
Information User Subsystem
Data Processing Subsystem Data Acquisition : from maps, images or field surveys. Data Input : data must be input from source material to the digital database.
Data Storage : how often is it used, how should it be updated, is it confidential?
Data Analysis Subsystem Retrieval and Analysis : may be simple responses to queries, or complex statistical analysis of large sets of data.
Information Output : how to display the results? As maps or tables? Or will the information be fed into some other digital system ?
Information User Subsystem Users may be researchers, planners, managers.
It provides interaction between GIS group and users to plan analytical procedures and data structures.
Ideal GIS Data from Maps Tabular data Field data Data from other digital database Remote sensing Global positioning system Reports Maps Photographic products Statistics To other digital database Input to Models Geographic Information System Database Management