Abstract
The Cross-track infrared Sounder (CrIS) on Suomi National Polar-orbiting Partnership Satellite (NPP), is a very important Fourier transform spectrometer, and provides soundings of the atmosphere with 1305 channels for low resolution SDR. The full resolution SDR data with spectral resolution of 0.625 cm-1 for all three CrIS bands (total 2211 channels) are generated using ADL. Quantifying the CrIS radiometric and spectral accuracy are crucial for using CrIS data in the satellite data assimilation systems that lead to improve weather forecasting. In this study, CrIS full resolution SDR radiometric and spectral accuracy are accessed by using the Community Radiative Transfer Model (CRTM). The biases between observation and simulations are evaluated to estimate the FOV-2-FOV variability and sweep direction bias for clear sky over ocean. A double difference method is used to assess the CrIS radiance consistency with well-validated IASI, and a cross-correlation method between observations and CRTM simulations is used to assess the CrIS spectral accuracy. Long-term CrIS low resolution SDR radiometric and spectral stability will also be presented.
Assessment of CrIS Full Resolution SDR Radiometric and Spectral Accuracy
The Cross-track infrared Sounder (CrIS) on Suomi National Polar-orbiting Partnership Satellite (NPP), is a very important Fourier transform spectrometer, and provides soundings of the atmosphere with 1305 channels for low resolution SDR. The full resolution SDR data with spectral resolution of 0.625 cm-1 for all three CrIS bands (total 2211 channels) are generated using ADL. Quantifying the CrIS radiometric and spectral accuracy are crucial for using CrIS data in the satellite data assimilation systems that lead to improve weather forecasting. In this study, CrIS full resolution SDR radiometric and spectral accuracy are accessed by using the Community Radiative Transfer Model (CRTM). The biases between observation and simulations are evaluated to estimate the FOV-2-FOV variability and sweep direction bias for clear sky over ocean. A double difference method is used to assess the CrIS radiance consistency with well-validated IASI, and a cross-correlation method between observations and CRTM simulations is used to assess the CrIS spectral accuracy. Long-term CrIS low resolution SDR radiometric and spectral stability will also be presented.