Module 1: Introduction to GIS

1
Module 1Introduction to GIS
2
What is GIS?

• A geographic information system
• manipulates, summarizes, queries, edits and
  visualizes geographic data
• A GIS uses information about what is where on the
  Earth's surface

3
Another description of GIS
GIS is a system of hardware, software and
procedures designed to support the capture,
management, manipulation, analysis, modeling and
display of spatially-referenced data for solving
complex planning and management problems
4
GIS Concept
The concept is to have Spatial Features (features
defined by location) in addition to Attributes
(features defined by what it is).
Non-Spatial Data (Attributes) stored in a database
Spatial Data
5
GISs contain

• Information about where something is. This is
  called location
• Information about what something is . These are
  called attributes.
• GIS can be detailed such as location of all trees
  in a city
• GIS can be general such as the overall climate of
  a region
• GIS can be static such as location of a monument
• GIS can de dynamic such as changing events like
  weather

6
Geographic Information

• Is digital in a GIS
• coded in a binary system that uses only two
  characters (0 or 1), called bits
• a package of information in digital form looks
  like any other package of information binary
  data is binary data. There is nothing special
  about it.
• many forms or types of information can be handled
  by the same technology
• a disk, DVD, CD, flash drive, hard drive, etc.
  can store words, numbers, maps, sounds

7
Geographic Information Technologies

• There are three types
• Global Position Systems
• Remote Sensing
• Geographic Information Systems

8
Why go to the trouble of building a GIS to handle
geographic information?

• easy to store, retrieve, query, manipulate, send,
  receive, copy, display...
• All these things can be done without a computer,
  but that is slow
• paper maps are difficult to handle, store, send,
  receive, copy and they are perishable
• Questions that have too many variables to be
  studied in a linear manner such as complex
  traffic optimization problems can be solved only
  by a GIS

9

• Essential hardware for a GIS include
• Computer, keyboard, display monitor
• Optional Input and Output devices are
• Printers
• Plotters
• Scanners
• Digitizers
• Internet access

10

• What simple tasks can a GIS perform?
• display data
• Edit and transform data
• measure distances, areas and angles
• combine maps
• Quantify topological relations
• Isolate homogeneous attributes
• Efficiently update maps

11
More complicated GIS Functions

• Inventory spatially diverse merchandise (i.e.
  Amazon.com)
• Perform site suitability analysis
• Assist decision makers
• Document trends
• Perform optimization routines

12
GIS Software

• user combines GIS software with data and performs
  various functions. You need both the software and
  data.
• GIS software is different than image processing
  software or AutoCAD software
• the price of the software ranges from free to
  
• There are free public domain GIS software
  programs, but most are provided by the private
  sector
• there are a handful of GIS software vendors
• some specialize in GIS such as ESRI
• for others, GIS is one of many markets for their
  products such as Intergraph

13
GIS Applications

• Utilities
• Utility companies (gas, electric, water,
  wastewater, solid waste) have millions of
  customers on a network composed of old and new
  infrastructure
• miles of wires, underground pipes
• transformers, switches, poles...
• Many of the maps are based on a base map that
  were made decades ago and so is incorrect from
  the absolute accuracy perspective.
• Receive many maintenance calls and must
• keep track of activity
• maintain accurate information about what is where
  
• keep records up to date
• make work assignments to crews
• provide information to others
• Outside organizations may need to dig up a
  street and so need an accurate account of what is
  where
• Delivery
• DHL, Fed Ex and UPS need to
• Keep track of trucks, planes, ships
• Plan most efficient routes

14
GIS Applications

• Emergency (E911) services rely on GIS
• a delivery company needs to keep track of
  shipments and plan efficient delivery routes
• Public transportation operators need to plan
  efficient collection routes
• a transit authority needs to know where transit
  vehicles are at all times
• The FAA recently announced a major revamping of
  the nations air traffic control system and it
  would be based on GPS and GIS technology

15
GIS Project Stages

• define the problem
• acquire the software and hardware
• acquire the data
• clean the database
• perform the analysis
• interpret and present the results

16
Disciplines of GIS

• Cartography map-making
• remote sensing Earth observation from the sky
  and space
• GPS determines point positioning using satellite
  observations
• Geodesy measurement of the Earth
• Surveying accurate measurement of natural and
  man made features
• Photogrammetry measurement from photographs and
  images
• image processing handling and analysis of images

17

• Disciplines that Apply GIS
• surveying
• geology
• geophysics
• oceanography
• agriculture
• forestry
• soil science
• biology
• ecology
• zoology
• environmental science
• anthropology