Atmospheric Windows

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Atmospheric Windows

• A range of wavelengths over which there is
  relatively little absorption of radiation by
  atmospheric gases
• Major windows
• 0.3 0.9 µm (visible window)
• 8 13 µm (infrared)
• Window goes away when air is very humid and/or
  there are clouds present
• gt 1 mm

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Atmospheric Windows
Microwave Window
Vis Window
IR Window
Atmospheric Opacity
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GOES Sensors - Imager

• Visible Channel (0.55 0.75 µm)

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GOES Sensors - Imager

• Moisture Ch. 3 (6.5 7.0 µm)

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GOES Sensors - Imager

• Infrared Ch. 4 (10.2 11.2 µm)

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Radiometers

• Measures radiant flux of E-M radiation
• Incident radiation heats sensor
• Temperature change is proportional to the power
  intercepted by the instrument
• Can be active (sends out pulse and measures
  backscatter) or passive (measures upwelling
  radiation from source)

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GOES Sounder (Radiometer)

• Covers visible spectrum to 15 µm
• Produces soundings of temperature/moisture

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Advanced Microwave Scanning Radiometer (AMSR)

• Passive
• On board AQUA satellite, developed by JAXA
  (Japanese Space Agency)
• Detects faint microwave signals
• Water vapor, precipitation, SST, wind speed, sea
  ice can be retrieved

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Special Sensor Microwave Imager (SSM/I)

• Passive radiometer
• On board Defense Meteorological Satellite Program
  (DMSP) satellites
• Can retrieve SST, rainfall, wind speed

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