COMPARISON OF BROAD-BAND AND HIGH-SPECTRAL-RESOLUTION INFRARED OBSERVATIONS

This note compares observations from two instruments with different spectral resolutions. The High-resolution Interferometer Sounder (HIS) observed radiances have a spectral resolution capable of differentiating individual absorption bands within the 600-2700cm(-1) (3.7-17 mu m) regime, the Earth Radiation Budget Experiment (ERBE) measures broadband (4-200 mu m) longwave fluxes. To derive broadband fluxes, ERBE processing must account for the spectral response function of the scanning instrument. As the HIS has the spectral resolution to simulate various filter response functions, the HIS observations are employed in a cross-validation of the spectral correction algorithm applied by the ERBE software processing. This is the only independent method of cross validating the first step in the processing of ERBE measurements. In addition, the HIS spectral measurements are integrated and compared with the ERBE broadband longwave fluxes. These comparisons demonstrate the complimentary nature of the two instruments for studying Earth radiation budget processes.