Transcript Introduction to Remote Sensing and GIS

Introduction to Remote
Sensing and GIS
REM 611 REMOTE SENSING AND GEOGRAPHIC
INFORMATION SYSTEM APPLICATION
Dr HALILU AHMAD SHABA
PANSHARPENED IMAGE OF NIGERIASAT-2 (ABUJA)
The Class
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REM 611 REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEM APPLICATIONS
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Introduction of Remote Sensing and Geographic Information System
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Remote sensing Applications to Disaster Management
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Types and Sources of Remote Sensing and Geographic Information Systems Data
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Data requirement for Disaster Management
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Information Generation for Decision Making
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Use of geo-information to visualize geographic data
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Remote Sensing Data Application to Hazard analysis and mapping
What we are going to cover on this
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Brief
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Introduction of Remote Sensing and Geographic Information systems
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
Remote sensing
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Definitions
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How it works/ principles
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EMR interactions
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Types of Remote Sensing
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History of Remote Sensing
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Advantages of Remote Sensing
Geographic information system
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What is GIS
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Components of GIS
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Advantages of GIS
DEFINITIONS OF RS
Remote Sensing: Defined
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General: “..it is the art or science of telling something about an object
without being in direct contact with it.” (Fisher et al. 1976; from Table 1.1 of
your text)
Remote Sensing: Defined
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More specific: “Remote sensing is the practice of deriving
information about the earth’s land and water surface using images
acquired from an overhead perspective, using electromagnetic
radiation in one or more regions of the electromagnetic spectrum,
reflected or emitted from the earth’s surface.” (Campbell)
Remote Sensing: Defined
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Obtaining information about Earth’s surface from measurements, by aircraft
or satellite sensors, of radiated energy
Remote Sensing: Defined
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Remote sensing is the science (and to some extent, art)
of acquiring information about the Earth's surface
without actually being in contact with it. This is done by
sensing and recording reflected or emitted energy and
processing, analyzing, and applying that information
(from Canadian Center for Remote Sensing).
How it works
Remote Sensing Process
Energy Propagation and usage
Remote Sensing is
more
particular
about
Reflected
Energy
Remote Sensing
 Relies
on detection, measurement, recording
and analysis of electro-magnetic (EM) energy
reflected or emitted from the objects of
interest on the surface of the earth.
 Different
objects return different types and
amounts of EMR and this is the basis for which
various objects, features and conditions are
assessed.
The electromagnetic spectrum
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All objects above absolute zero
electromagnetic radiation
(-273.15ºC or 0ºK) emit
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Nuclear reactions occur within the Sun which emits ER across a broad range of
wavelengths called a spectrum
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Some regions of this spectrum are visible (visible light) and some are invisible
(infrared or ultraviolet)
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Remote sensing relies on the measurement of this radiation
The electromagnetic Energy
Radiation from the Sun has a short
wavelength (shortwave). Radiation from
the Earth has a long wavelength
(longwave)
The shorter the wavelength the higher the frequency
The Electromagnetic Spectrum
μm = micrometer = 10-6 meters
The micrometer is the most common unit used to quantify the
wavelength of EM energy
Lillesand and Kiefer
Interactions of EM energy with earth surface features
Lillesand and Kiefer
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λ the greek letter “lambda” is the
symbol for wavelength
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This figure is really a statement about
the First Law of Thermodynamics. You
will recall that this law deals with the
conservation of energy.
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All incident EM energy of a particular
wavelength, λ, will be partitioned
among reflection, transmission and
absorption.
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This basic principle hold for solids,
liquids and gases.
Types of remote sensing
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Passive: source of energy is
either the Sun or
Earth/atmosphere
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Active: source of energy is part
of the remote sensor system
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Sun
Radar
- wavelengths: mm-m
- wavelengths: 0.4-5 µm
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Earth or its atmosphere
- wavelengths: 3 µm -30 cm
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Lidar
- wavelengths: UV, Visible, and
near infrared
Camera takes photo as example, no flash and flash
REMOTE SENSING HISTORY
• Remote sensing began
in 1840 when balloonists
used “new camera
technology”
to take pictures.
• At the turn of the
century were
“pigeon fleet” in Europe.
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• Camera systems
were placed on V-2
rockets tested at
White Sands, NM
after WW II.
• Sputnik in 1957
changed our outlook
toward using outer
space as a place from
which to observe the
earth.
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Milestones in the history of Remote Sensing
1800 :
Discovery of infrared by Sir William Herschel
1839:
Beginning of practice of photography
1847:
share
Infrared spectrum shown by A. H. L. Fizeau & J.B.L. Foucault to
properties with visible light
1850-1860: Photography from balloons
1873:
Maxwell
1909:
Theory of electromagnetic energy developed by James Clerk
Photography from airplanes
1914-1918: World War 1: aerial reconnaissance
1920-1930: Development & initial application of aerial photography &
photogrammetry/ routine use of aerial photos by various government
agencies
1929-1939: Economic depression generates environmental
crises that lead
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to
governmental application of aerial photography.
Milestones in the history of Remote Sensing
1930-1940: Development of radars in Germany, US & UK
1839-1945: World War II: application of nonvisible portions of
electromagnetic spectrum, Development of infrared films training of
persons in acquisition and interpretation of airphotos.
1950-1960: Military research and development for intelligence gathering
1850-1860: Photography from balloons
1956:
Colwell research on plant disease detection with infrared
photography.
1960-1970: First use of term “remote sensing”, start TIROS weather
satellite, Skylab, development of digital image processing with
multispectral scanners
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Milestones in Remote Sensing
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1972: The launch of the Earth Resources Technology Satellite
(ERTS-A); later renamed LANDSAT I. This was the first satellite
dedicated to civilian remote sensing
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1970-1980: Rapid advances in digital image processing
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1980-1990: Landsat 4: new generation of Landsat sensors
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1986: SPOT French Earth Observation satellite
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1980: Development of hyperspectral sensor
3 broad categories of spatial
resolution available
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High resolution (0.6-5m)
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Moderate (10-80m)
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IKONOS, Quickbird, Orbview, NigeriaSat-1
MSS, TM, SPOT, Aster, NigeriaSat-1
Low (250m – 4km)
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AVHRR, MODIS
Field of Application
Wageningen 1999
ADVANTAGES OF REMOTE SENSING
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Improved vantage point, synoptic view
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Broadened spectral sensitivity and amenability
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Increased spatial resolution
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3-D perspective
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Historical record
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Rapid data collection and repeat coverage
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Quantitative analysis
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Cost savings
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Multiple use