Intercalibration of advanced Himawari-8 Imager's infrared channels with IASI/Metop-B 1C data

This paper addresses the intercalibration of the infrared channels 7∼16 of Advanced Himawari-8 Imager (AHI8) against the hyperspectral channels of Infrared Atmospheric Sounding Interferometer (IASI) on Metop-B using the hyperspectral convolution method. Matching measurements in July of 2016 were collected over a tropical area (100° E∼180 ° E, 10 ° S∼ 10 ° N) with collocation, absolute observation time difference of less than 5 minutes, and |cosθ 1 /cosθ 2 -1| of less than 0.015, where θ 1 and θ 2 are, respectively, AHI8 and IASI/Metop-B viewing zenith angles. The results show that the AHI8 measurements are highly linearly related to the convolved IASI hyperspectral measurements, and intercalibration coefficients are obtained through linear regression on the matching measurements. Against the IASI hyperspectral channels, the in-orbit calibration biases in AHI8 infrared channels 7∼16 are, 0.09, −0.11, −0.16, −0.04, −0.03, −0.19, 0.07, 0.10, −0.02 and 0.16 K, respectively.