Inter-calibration of GOES-11 imagers with AIRS and IASI data

Abstract

The advent of hyperspectral sounders, such as the Atmospheric Infrared Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI), makes it possible for us to independently assess the radiance measurements of GOES Infrared (IR) imagers, which also provide an effective way to evaluate the GOES IR on-board calibration. In this study, we demonstrate the utility of the AIRS and IASI radiances to evaluate the GOES-11 IR channel measurements. We use the AIRS and IASI measurements to inter-calibrate the IR channels on GOES-11. The collocated GOES pixels inside each AIRS (IASI) pixel are averaged spatially. Then the spatially-averaged radiance from GOES IR channels are compared to AIRS (IASI) observations by convolving the AIRS (IASI) measured spectra with the GOES imager spectral response functions. This study demonstrates that the high-spectral resolution radiance measurements can serve as a relative reference for the inter-calibration of operational GOES imagers for the Global Space-based Inter-Calibration System (GSICS).