Introduction to Space Science Remote Sensing
Geographic Information Science
Shahanshah Abbas Space Science Department
shani@grel.ist.edu.pk
Outline:
• Introduction to Remote sensing
• Introduction to Geographic information science
• RS Comparison with GIS
• Examples of GIS
• GIS in Pakistan
• Representation of Spatial Data
• Coordinate system
• Grading Policy.
• Books / Materials used in this course.
GIS Learning With Python 2
Introduction
• First Sentence that comes to your mind when you see the word “Remote Sensing”.?
• First Sentence that comes to your mind when you see the word “GIS(Geographic
information Science)”.?
GIS Learning With Python 3
Introduction (RS)
• Remote sensing is the art of acquiring information about an object or phenomenon without making physical contact with the object.
• satellites or aircraft to capture information about the earth’s surface
• DSLR (ground remote sensing)
Introduction (GIS)
• GIS is a tool / system /phenomena for Capturing, Storing, querying and analyzing and displaying geospatial data.
Data
Characteristics Location
RS & GIS:
intuitive description
Components of a GIS
There are five components ...
People :
People are the most important component of a GIS because people must develop the procedures and define the task the GIS will perform
Data :
We manage manipulate and store geospatial data in GIS environment to extract spatially explicit information from it. Availability and accuracy of data affects the results of queries and analysis.
Hardware :
Hardware capabilities affect processing speed, ease of use and type of available output.
Software :
Include GIS software, database, drawing, Images and other software programs.
The software include source code and the user interface. The code may be written in C++, visual basic or python. Common user interfaces are menus, graphical icons, command lines and scripts.
Procedures:
GIS analysis requires well-define, consistent method to produce correct
results 7
Components of geographic data
Three main components to geographic data
Geometry : (Spatial)
Geometry represent the geographic feature associate with real- world locations
1. Point 2. line 3. polygons (areas)
Attributes: (Non Spatial)
Attributes are descriptive characteristics of the geographic feature . Name, Length, size, colour,
Behaviour:
Behaviour means that geographic features can be made to allow certain types of editing, display or analysis.
8
Examples of GIS
Urban Planning, Management & Policy
Zoning, subdivision planning Land acquisition
Economic development Code enforcement
Housing renovation programs Emergency response
Crime analysis Tax assessment
Environmental Sciences
Monitoring environmental risk Modeling storm water runoff
Management of watersheds, floodplains, wetlands, forests, aquifers
Environmental Impact Analysis Hazardous or toxic facility siting
Groundwater modeling and contamination tracking
Political Science
Redistricting
Analysis of election results Predictive modeling
Civil Engineering/Utility
Locating underground facilities
Designing alignment for freeways, transit Coordination of infrastructure maintenance
Business
Demographic Analysis
Market Penetration/ Share Analysis Site Selection
Education Administration
Attendance Area Maintenance Enrollment Projections
School Bus Routing
Real Estate
Neighborhood land prices Traffic Impact Analysis
Determination of Highest and Best Use
Health Care
Epidemiology Needs Analysis Service Inventory
GIS in Pakistan
• Local Government / NGO
– Public works/infrastructure management (roads, water, sewer) – Planning and environmental management
– property records and appraisal
• Real Estate and Marketing
– Retail site selection, site evaluation
• Public safety and defense
– emergency management, military/defense
• Natural resource exploration/extraction – Petroleum, minerals, quarrying
• Transportation
– Airline route planning, transportation planning/modeling
• Public health and epidemiology
• The Geospatial Industry
– Data development, application development, programming
Topography
• The study of features and the relationship on the surface of Earth from satellite. (How actually the surface of earth looks like)
• Features like mountains, Plain, Rivers etc.
Representation of Spatial Data
Vector Data
Spatial Data
Raster Data
Representation of Spatial Data (Cont.)
• Point, lines and polygons can also combined to give another feature
• Triangulated Integrated Network
• Elevation data , Precipitation Data
GIS Operation (In General) Con.t
• Data acquisition and prepressing.
• Data attribute acquisition
• Displaying data (Maps)
• Data Analysis
• Modeling of data
• Visualizing end product
GIS Operation (In General)
• Some of GIS data is freely Available
• For Latest and Best Resolution image you have to pay
Coordinate System
• To represent data compromising of Spatial features we need coordinate system.
• Coordinate systems are used to define the location of the object with some reference.
• Satellite images are not in Earths coordinates system.
Geographic Coordinate system
Longitude / Latitude Satellite
Image Reference system
Earth Reference system X,Y or X,Y,Z
Projections
Meridians
Parallel
Coordinate System (Cont.)
• Longitude and latitudes are measured in Degree Minutes and Seconds (DMS) or radians.
• 1 degree =60 minutes
• 1 minutes =60 seconds
• 1 rad covers almost 57.2958 degrees of earth
• 1 degree =1/57.2958=??
Coordinate System (Cont.)
• Mapping of Spatial features / objects on earth surface is done by a model to predict the size and shape of the Earth.
• Simplest model is Sphere model.
• Better approximation is sheroid (Ellipisod)
• Best approximation model of earth is geoid
Calculation of Geographic Coordinates
• Calculation of Geographic Coordinates is achieved through Datum.
• Datum is a mathematical model (Set of Reference Points )for calculating Geographic Coordinates (Lat/Long).
• Almost every Country Defines its own Datum.
• NAD 1983, WGS 84, NAD 27 etc.
