Advanced Microwave Sounding Unit
AMSU-A is a 15-channel microwave sounder designed primarily to obtain temperature profiles in the troposphere and stratosphere. Each AMSU-A instrument is composed of two separate units: AMSU-A2 with 2 channels at 23.8 and 31.4 GHz and AMSU-A1 with 12 channels in the range of 50.3–57.3 GHz plus 1 channel at 89.0 GHz. AMSU-A1 has a set of 12
oxygen band channels (3–14) for retrieving the atmospheric temperature profile from the Earth's surface to about 50 km in
altitude.
Precipitation,
sea ice,
snow cover, surface
emissivity, atmospheric liquid
water, and total
precipitable water are derived primarily from three window channels (23.8 and 31.4 GHz from AMSU-A2 and 89.0 GHz from AMSU-A1).
AMSU-B, later called the Microwave
Humidity Sounder (MHS) measures five microwave channels and accompanies AMSU-A: one channel in the 89-GHz "window" channel, one channel at 150 GHz, and remaining three channels around the 183-GHz water vapor line. The primary function of AMSU-B (MHS) is to obtain the water vapor profile in the troposphere and lower stratosphere.
Term edited 10 August 2021.
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