The AIRS Project Instrument Suite measures wavelengths from visible into the microwave. The regions were chosen to sample water at various altitudes, as well as emission wavelengths of other gasses that allow sounding, such as CO2 and O2.
The AIRS Vis/NIR photometer measures low-level clouds in the visible and NIR.
The AIRS spectrometer measures water vapor and trace gasses in the NIR, MWIR, and LWIR. AIRS has 17 detector array modules covering a continuous spectral range for each module. The spectral range for each module is shown in the table below.
| Module Name||Start ν (cm-1)||End ν (cm-1)|
Channels 1-2: surface and moisture
Channels 3-14: oxygen absorption band, providing the primary temperature sounding
Channel 15: surface and moisture (total precipitable water and cloud liquid water)
(AMSU-B channel numbers):
Channel 17: 150 GHz deeper penetration through the atmosphere to the Earth's surface
Channels 18-20: span the strongly opaque water vapor absorption line at 183 GHz and provide data on the atmosphere's humidity level