Department of Geomatics Remote Sensing Applications

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Department of Geomatics Remote Sensing
Applications

• Geological Remote Sensing
• Airborne Geophysics

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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics

• Four Major Techniques will be considered
• Aeromagnetics
• Airborne Radiometrics
• Airborne Electro/Magnetic Survey
• Airborne Gravity

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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics

• All of these techniques
• Can be used as input to numerical modelling of
  the subsurface (not considered here)
• Can be used to generate image data
• Need detailed topographic information to make the
  required terrain corrections.

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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics

• All of these techniques
• Sample along a series of flight lines
• Are unfocussed, and so sample a large area
  beneath the flight line
• Use interpolation between the flight lines to
  construct an image

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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics

• All of these techniques
• Have a high sample along the flight lines
• Have a relatively large spacing between flight
  lines
• Use minimum curvature or spline interpolation to
  about 1/5 flight line spacing
• Resample along the flight line to produce regular
  grids

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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics

• Aeromagnetics
• Detects natural variations in the Earths
  magnetic field
• Different rock types have different magnetic
  properties (due to minerals such as Iron Oxides
  etc.)
• Flown on specially modified aircraft - a boom
  separates the magnetometer from airframe
  interference

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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics
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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics

• Aeromagnetics
• Directional filters often used to provide
  illumination over the magnetic terrain.
• This allows for easier interpretation
• Shows more detail

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Department of Geomatics Remote Sensing
Applications
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Department of Geomatics Remote Sensing
Applications
AEROMAGNETICS Helicopters are often used for
detailed, high resolution surveys
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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics

• Radiometics
• Detects the natural radioactivity of the Earth
• Due to the decay of radioactive isotopes found in
  common minerals
• Flown at the same time as aeromagnetics
• Samples the first 30-40cm

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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics Radiometics
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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics

• Airborne Electro/Magnetic Survey
• Does NOT use the electromagnetic spectrum
• Generates an artificial magnetic field to induce
  a current in the ground
• This induced current produces a secondary
  magnetic field which is detected

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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics

• Airborne Electro/Magnetic Survey
• Detects conductive layers or areas within the
  ground
• Uses a specially modified aircraft with a wire
  loop all the way around

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Department of Geomatics Remote Sensing
Applications
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Department of Geomatics Remote Sensing
ApplicationsAirborne Geophysics
Airborne Electro/Magnetic Survey A Paleo-river
Channel in WA
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Department of Geomatics Remote Sensing
Applications
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Department of Geomatics Remote Sensing
Applications
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Department of Geomatics Remote Sensing
Applications
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Department of Geomatics Remote Sensing
Applications
Falcon Airborne Gravity System
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Department of Geomatics Remote Sensing
Applications
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Department of Geomatics Remote Sensing
Applications
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Department of Geomatics Remote Sensing
Applications
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Department of Geomatics Remote Sensing
Applications