RS and GIS: UWGB 2011
Dutch, Fermanich and Stiefvater
Remote Sensing
http://www.cas.sc.edu/geog/rslab/Rscc/rscc-frames.html
What is Remote Sensing?
• Acquisition of physical data of an object without
touch or contact.
• Observation of a target by a device separate
from it by some distance.
• ”Reconnaissance at a distance.”
• Depends on context.
• Some definitions include Geophysical (seismic,
magnetic, gravitational, acoustical, & nuclear
decay radiation surveys)
• These days usually implies more than mere
visual processing
What Sensors Detect
• Electromagnetic radiation
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Radio
Infrared (thermal)
Visible
Ultraviolet
X-Ray and gamma ray
• Force fields
– Gravity
– Magnetism
• Acoustic energy
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Audible
Ultrasonic
Infrasonic
Seismic
Sensors
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Cameras
Radiometers and scanners
Lasers
Radio frequency receivers
Radar systems
Sonar
Thermal devices
Seismographs
Magnetometers
Gravimeters
Scintillometers
Fig. 18-2, p.430
Remote Sensing
http://www.cas.sc.edu/geog/rslab/Rscc/rscc-frames.html
• Source of the radiation
being sensed may or may
not be independent of the
sensing device.
• Passive remote sensing
relies on the radiation
originating from some
other source, principally
the sun.
– Often Visible, NIR
• Source of the radiation being
sensed may or may not be
independent of the sensing
device.
• Active remote sensing devices,
such as radar, direct radiation of
a particular form towards an
object and then detect the
amount of that energy which is
radiated by the object.
– microwave and radio wave regions
of the EM spectrum.
– Lidar (Laser Imaging raDAR)
systems :ultraviolet, visible and near
infrared wavelengths.)
Physical Object
Sensor Data
Extracted Info
Applications
GIS
Land Use
Geology
Hydrology
Vegetation
Soils
Geographic Information
Systems (GIS)
• Data
– Vector
– Raster
• Metadata (Data About the Data)
– When, how, by whom acquired
– What the data means
– How accurate is the Data
– How the Computer should deal with Data
Image of the day
• Where:
Southern
Chile
• When:
January
19, 2009
Chaiten Volcano, Chile
Image of the day
• Where: Southern Chile
• When: January 19, 2009
• What’s being sensed?
– Ash plume and previous ash falls
– Dispersal patterns and paths
• Advanced Spaceborne Thermal Emission and
Reflection Radiometer (ASTER)
– Multi spectral including visible and IR
• Satellite: NASA’s Terra (launched Feb. 2000)
Why Chaiten is Neat
Image of the Day
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Rehearse
Scale, location, orientation
Be able to pronounce terms correctly
Anticipate questions
– Effects on people and environment
– Unusual features in image
– How data acquired