Sensitivity experiments of spectral coverage

channel coverage and bandwidth are performed to investigate the channel characteristics designed to meet the basic requirements of atmospheric profile retrieval accuracy of 1K for temperature and 20% for humidity in 1 km thick tropospheric layers.Temperature and humidity profiles are retrieved from AIRS（Atmospheric Infrared Sounder） real measurements via empirical orthogonal function（Eigenvectors of Covariance Matrix） expansion methodology.Results suggest that notable improvements of the atmospheric parameter retrieval accuracy can be achieved by developing infrared interferometric spectrometer/radiometer with about 100 channels and with bandwidth of 2—4 wave numbers on the current technical and economical basis of our country.This bandwidth is 3—4 times smaller than that of the earlier spectrometer/radiometer on FY-3 satellite which will be launched in the year of 2006.