Acta Optica Sinica, Volume. 39, Issue 11, 1130003(2019)
Radiation Calibration Accuracy Assessment of FY-3D Hyperspectral Infrared Atmospheric Sounder Based on Inter-Comparison
High-precision radiometric calibration of hyperspectral infrared sounders is crucial for its quantitative application. In this study, the relative deviation obtained by radiance calibration of infrared hyperspectral atmospheric sounder (HIRAS) on FY-3D satellite is evaluated based on infrared atmospheric sounding interferometer (IASI) on European meteorological satellites MetOp-A and MetOp-B and Y-3D satellite through simultaneous nadir overpass. According to the observation data of strictly spatial and temporal matching of both instruments, the uniform scenes are selected by using the higher spatial resolution data of medium resolution spectral imager (MERSI-II) on the same platform of FY-3D. The spectral resolution of IASI data is converted to the same spectral resolution of HIRAS through forward-inverse Fourier transform method before inter-comparison. Because the matching samples which satisfy the collocation criteria are distributed in the North and South Arctic regions with low target temperatures, the inter-comparison results are evaluated by mean and standard deviation of HIRAS-IASI brightness temperature (BT). The results show that the comparison results between HIRAS and MetOp-A/B are similar, the consistency of North Arctic regions with high temperature is better than that of South Arctic regions. HIRAS agrees well with IASI at the long-wave IR (LWIR) and middle-wave IR (MWIR) in low temperature environment with less than 1 K mean deviation and below 0.5 K in most channels. There are no apparent scene-dependent features for individual spectral channels, the standard deviation is less than 2 K, and varies with the spectral channels, slightly larger at the position where the absorption line is sharp. The spectral BT of HIRAS is lower than that of IASI with <1.5 K mean deviation in most channels at short-wave IR (SWIR), the deviation shows scene-dependent features, and the standard deviation decreases as the target temperature increases. The long-term trend of BT difference (from April to December, 2018) analysis shows that long-term consistency of HIRAS is stable, the mean deviation at SWIR is slightly larger in the lower target temperature conditions.
Get Citation
Copy Citation Text
Tianhang Yang, Xiuqing Hu, Hanlie Xu, Chunqiang Wu, Chengli Qi, Mingjian Gu. Radiation Calibration Accuracy Assessment of FY-3D Hyperspectral Infrared Atmospheric Sounder Based on Inter-Comparison[J]. Acta Optica Sinica, 2019, 39(11): 1130003
Category: Spectroscopy
Received: Jun. 20, 2019
Accepted: Jul. 24, 2019
Published Online: Nov. 6, 2019
The Author Email: Hu Xiuqing (huxq@cma.gov.cn)