2. Topics Covered
GIS – Geographic Information System
• Introduction to GIS
• Geospatial data
• Components of GIS
• Application of GIS
RS – Remote Sensing
• Introduction to RS
• Information Extraction from Remote Sensing Imagery
• Types of RS
• Application of RS
3. Geospatial Data
• Also called geographically referenced data
• Geospatial data are data that describe both the locations and the
characteristics of the spatial features such as roads, land parcels,
and vegetation stands on the Earth’s surface.
• To describe a road, we refer to its location (i.e. where it is) and its
characteristics (e.g.: length, name, speed, limit and direction)
• The location, also called geometry or shape, represents spatial data,
whereas the characteristics are attribute data.
4. Introduction to GIS
• A geographic information system (GIS) is a computer system designed to capture,
store, manipulate, analyze, manage and present all types of spatial or
geographical data.
• GIS applications are tools that allow users to create interactive queries (user
created searches), analyze spatial information, edit data in maps and present the
results of all these operations.
7. Contd…
1. Computer System (Hardware)
The computer system includes the computer and the operating system to run
GIS.
Additional equipment may include monitors for display, digitizers and
scanners for spatial data input, GPS receivers and mobile devices for fieldwork
and printers and plotters for hard-copy data display.
8. Contd…
2. Software
The GIS software includes the program and the user interface for driving the
hardware. Common user interfaces in GIS are menus, graphical icons,
command lines, and scripts.
Software provides the functions and tools required to store, analyze and
display the spatial data.
This includes the GIS software, database and the drawing software.
9. Contd…
3. Data
Data is the core of any GIS.
Data consist of various kinds of inputs that the system takes to produce
information.
There are two types of data used in a GIS - spatial and tabular (also known
as attribute data).
The availability and accuracy of data will affect the results of any analysis.
A GIS can integrate data from a number of different sources and store in a
database management system.
10. Contd…
4. People
People refers to GIS professionals and users who define the purpose and
objectives and provide the reason and justification for using GIS.
GIS users range from technical specialists who design and maintain the
system to those who use it to help them perform their everyday work.
11. Contd…
5. Infrastructure
The infrastructure refers to the necessary physical, organizational,
administrative and cultural environments that support GIS operations.
The infrastructure include requisite skills, data standards and general
organizational patterns.
15. 15
07/06/2025
GIS may aid in disaster assessment and recovery. These satellite images from Banda Aceh, Indonesia,
illustrate tsunami-caused damage to a shoreline community. Emergency response and longer term
rebuilding efforts may be improved by spatial data collection and analysis(courtesy Digital Globe).
22. Contd…
• In remote sensing, the sensors are not in direct contact with the objects or events
being observed.
• The information needs a physical carrier to travel from the objects/events to the
sensors through an intervening medium.
• The electromagnetic radiation is normally used as an information carrier in
remote sensing.
• The output of a remote sensing system is usually an image representing the scene
being observed.
• A further step of image analysis and interpretation is required in order to extract
useful information from the image.
23. Contd…
Process Involved
A – Energy Source or Illumination
B – Radiation and the Atmosphere
C – Interaction with the Target
D – Recording of Energy by the Sensor
E – Transmission, Reception and Processing
F – Interpretation and Analysis
G - Application
24. 24
Why remote sensing?
• Synoptic view (Large areas, dense data)
• For real time measurements
• High repeatability
• Global, inaccessible/secure areas
• Multi purpose
• Cost effective (can be)
07/06/2025
25. Types of RS
1. Passive Remote Sensing
• Remote sensing systems which measure energy that is
naturally available
• Sun is the major source of energy
• Passive sensors can only be used to detect energy when
the naturally occurring energy is available.
• Energy that is naturally emitted (such as thermal infrared)
can be detected day or night, as long as the amount of
energy is large enough to be recorded.
26. Types of RS
2. Active Remote Sensing
• Remote sensing systems where the energy is emitted to
scan the objects and areas whereupon a sensor then
detects and measures the radiation that is reflected or
backscattered from the target.
27. Application of RS
• Environmental assessment and monitoring (Urban growth, hazardous waste)
• Global change detection and monitoring (atmospheric ozone depletion,
deforestation, global warming)
• Agriculture (crop condition, yield prediction, soil erosion)
• Non-renewable resource exploration (minerals, oil, natural gas)
• Meteorology (atmosphere dynamics, weather prediction)
• Mapping (topography, land use, civil engineering)
• Military surveillance and reconnaissance (strategic policy, tactical assessment)
30. Data Source:
• Landsat: landsat.usgs.gov or www.earthexplorer.usgs.gov
• AVHRR: http://nsidc.org/data/avhrr/
• MODIS: http://modis.gsfc.nasa.gov/
• MODIS Level 1 data, geolocation, cloud mask, and Atmosphere products:
http://ladsweb.nascom.nasa.gov/
• MODIS land products: https://lpdaac.usgs.gov/
• MODIS cryosphere products: http://nsidc.org/daac/modis/index.html
• MODIS ocean color and sea surface temperature products:
http://oceancolor.gsfc.nasa.gov/
