GOES High-Resolution Interferometer Sounder Retrieval Performance Simulations'

ABSTRACT . Anevolutionaiy improvement to the existing GOES I-M Sounder has been proposed as the GOES High..Resolution Interferometer Sounder (GHIS). This instrument will be based upon technology developed during successful demonstrations of an airborne Michelson interferometer instrument for the temperature and moisture sounding of the atmosphere from passive infrared measurements. The spectral resolution afforded by the interferometer technology will substantially improve retrieval accuracy and vertical resolution of the sounding information. Simulations of the spectral radiance measurements have been used to study the expected retrieval performance of the GillS. A fast transmittance code has been used in the simulations and in the calculation ofthe retrieval operator in an iterative, non-linear physical retrieval scheme. The effects of instrument noise and spectral operating mode have been considered in the retrieval simulation. A measure of the vertical resolution of the retrieved profiles has been developed. This measure considers the correlation in the retrieval error between atmospheric levels of the retrieved parameters. The effects of both the instrument characteristics and those of the retrieval algorithm are thus considered in this measure. The results indicate that the GHIS is expected to provide temperature retrieval accuracy on the order of I °C throughout the troposphere which will be a significant improvement over the existing GOES-8 sounder. The vertical resolution simulations also show improvement over GOES-8 capabilities.