The preparation of the launching of Greenhouse gases Observing SATellite-2 (GOSAT-2) in fiscal 2017 has been progressing. GOSAT-2 will be equipped with two earth-observing instruments: the Thermal And Near-infrared Sensor for carbon Observation Fourier Transform Spectrometer 2 (TANSO-FTS-2), and the Cloud and Aerosol Imager 2 (TANSO-CAI-2). Cloud contamination within the instantaneous field-of-view (IFOV) of the FTS-2 leads to incorrect estimates of major greenhouse gases concentration. Thus, cloud-contaminated FTS-2 data will be identified and rejected using the CAI-2. The observed time difference between the FTS-2 and CAI-2 may be longer than the FTS and CAI because the CAI-2 is a push-broom imaging sensor which has the backward and forward looking bands. Consequently, we examined the probability of cloud contamination within the IFOV of the FTS-2 by moving cloud though it was cloud-free region when the CAI-2 observed there. And we propose a method using the CAI-2 cloud discrimination for screening of cloud-contaminated FTS-2 data.
