The IASI instrument measures infrared radiation emitted from the surface of the Earth to derive atmospheric temperature and humidity profiles of unprecedented accuracy and vertical resolution. The high resolution allows small concentrations of atmospheric gases to also be derived.
IASI will supply:

• Temperature profiles in the troposphere and lower stratosphere with an accuracy of 1° Kelvin and a vertical resolution of 1 kilometre in the lower troposphere.
• Humidity profiles in the troposphere with an accuracy of 10% and vertical resolution of 1 kilometre in the lower troposphere.
• The total amount of ozone in a column with an accuracy of 5% and fractional cloud cover and cloud top temperature and pressure.
• Sea and land surface temperatures
  In addition, IASI will measure the total column content of the main greenhouse gases.