The EOS MLS measures thermal emission from broad spectral bands centered near 118, 190, 240, 640 and 2500 GHz.
They are measured continuously (24 hours per day) by 7 microwave receivers (2 each at 118 and 2500 GHz) using a limb viewing geometry, which maximizes signal intensities and vertical resolution.
MLS is radiometrically calibrated after each 25 second limb scan. Design lifetime is 5 years of continuous operation.
The EOS MLS instrument contains three modules.
- The GHz radiometer module, which includes the 118 through 640 GHz receivers and a scanning offset antenna with 0.8 x 1.6 m primary mirror.
- The THz radiometer module which contains the 2500 GHz receivers and the THz telescope and scan mirror, whose scan is synchronized with that of the GHz antenna.
- The Spectrometer module which receives signals from the GHz and THz radiometer modules, detects and digitizes them, and passes the digitized signals to the spacecraft for telemetry to the ground.
|Radiometer||Primary Data Products||Additional Data Products|
|Geopotential Height||Tangent Pressure|
|HNO3 (upper troposphere)||IWC|
|RHI||N2O (Lower Quality than from 640 GHZ)|
|O3 (but not in upper trop)|
|240 GHz||CO||Improves Quality of Upper Trop H2O|
|HNO3 (Upper Troposphere and Lower Stratosphere)|
|HCl||Stratospheric O3 with better vertical resolution than 240 GHz, but not in upper troposphere.|
|HO2||Improves quality of upper trop H2O|
|2.5 THz||OH||O3 (Lower quality than from other radiometers)|
* For v4 and later, the standard N2O product comes from the 190 GHz. The 640 GHz N2O product is of slightly higher quality than the 190 GHz, but the record ends in June 2013.