Department of Geomatics Remote Sensing

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Department of Geomatics Remote Sensing

• ELECTROMAGNETIC RADIATION

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Department of Geomatics Remote
SensingElectromagnetic Radiation

• Perpendicular electrical and magnetic variations

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Department of Geomatics Remote
SensingElectromagnetic Radiation

• Characterised by frequency (f) or
• Characterised by wavelength (??
• f C / ?

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Department of Geomatics Remote Sensing
Electromagnetic Radiation Black Body Radiation

• Emitted by all matter above absolute zero
• Both energy and maximum frequency dependent on
  temperature

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Department of Geomatics Remote Sensing

• Black Body Radiation

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Department of Geomatics Remote Sensing
Electromagnetic Radiation Black Body Radiation

• Water is a good approximation of a black body
  (grey body)

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Department of Geomatics Remote Sensing
Electromagnetic Radiation Black Body Radiation

• Quartz is not a good approximation of a black
  body (selective radiator)

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Department of Geomatics Remote
SensingElectromagnetic Radiation

• Energy is inversely proportional ?
• Planks Law
• E C.h /?????

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Department of Geomatics Remote
SensingElectromagnetic Radiation

• Energy of EM directly proportional to f
• Energy determines interaction with matter

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Department of Geomatics Remote
SensingElectromagnetic Radiation
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Department of Geomatics Remote
SensingElectromagnetic Radiation
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Department of Geomatics Remote Sensing

• f also determines interaction with atmosphere

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Department of Geomatics Remote
SensingElectromagnetic Radiation

• We view the Earth through atmospheric windows

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Department of Geomatics Remote
SensingElectromagnetic Radiation

• Visible and IR region atmospheric windows

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Department of Geomatics Remote
SensingElectromagnetic Radiation

• Microwave region atmospheric window

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Department of Geomatics Remote
SensingElectromagnetic Radiation

• Atmospheric path can act to block and alter
  signal
• Need to be compensated for
• Normalisation
• Dark pixel
• Multi-temporal standardisation
• Atmospheric calibration