Comparison of AMSU temperature soundings with those produced by HIRS and AMTS

The new generation of satellite borne radiometers to be launched in the late 1980's or early 1990's are currently planned to have as their main temperature sounding unit the AMSU (Advanced Microwave Sounding Unit). This device consists of two units, one of which contains 11 high spectral and spatial resolution channels which are to be used to produce vertical atmospheric temperature soundings. Other channels are to be used to determine atmospheric liquid water and water vapor amounts, as rain detectors, and for surface emissivity determination. This report, however, shall deal only with the accuracy of temperature retrievals. Toward this end studies have been carried out in which atmospheric temperature profiles were retrieved from simulated radiances for the AMSU channels. As a comparison, atmospheric temperature profiles were retrieved from simulated radiances for the currently operational HIRS infrared sounder as well as the proposed advanced infrared sounder AMTS. All simulations were based on a set of 400 mid-latitude radiosondes.