Title
First Assessment Of Hy-1c Cocts Thermal Infrared Calibration Using Metop-B Iasi
Abstract
The Chinese Ocean Color and Temperature Scanner (COCTS) onboard the Haiyang-1C (HY-1C) satellite was launched in September 2018. Accurate and stable calibration is one of the important factors when deriving geophysical parameters with high quality. The first assessment of HY-1C COCTS thermal infrared calibration is conducted in this research. We choose the Infrared Atmospheric Sounding Interferometer (IASI) onboard the MetOp-B satellite as the reference instrument, mainly due to its hyper-spectral characteristic and accurate calibration superiority. The brightness temperatures (BTs) from the two HY-1C COCTS thermal infrared bands centered near 11 and 12 mu m are collocated with the IASI in the spatial window of 0.12 degrees x 0.12 degrees and temporal window of half an hour. The homogeneity filtering of matchups is also carried out by setting the relative standard deviation (RSD) thresholds on each collocated grid and its neighboring grids. Based on the filtered matchups, the HY-1C COCTS BTs from the 11 and 12 mu m channels are compared with IASI. The mean differences of COCTS minus IASI are 2.68 and 3.18 K for the 11 and 12 mu m channels, respectively. The corresponding standard deviations (SDs) are also 0.29 and 0.28 K, respectively. In addition, the BT differences show latitude-dependence and BT-dependence. In order to correct the HY-1C COCTS thermal infrared BTs, the latitude-dependent coefficients are obtained to express the relationship between the BT differences and IASI BTs using the linear robust regression. After the BT correction, the biases and BT-dependence of the COCTS original BT minus IASI differences are removed. Further, the SDs decrease to 0.21 K for the 11 and 12 mu m channels. Overall, the calibration of the HY-1C COCTS thermal infrared channels remains stable and the accuracy is around 0.2 K after inter-calibration.
Year
DOI
Venue
2021
10.3390/rs13040635
REMOTE SENSING
Keywords
DocType
Volume
Haiyang-1C (HY-1C), Chinese Ocean Color and Temperature Scanner (COCTS), Infrared Atmospheric Sounding Interferometer (IASI), thermal infrared, calibration
Journal
13
Issue
Citations 
PageRank 
4
0
0.34
References 
Authors
0
6
Name
Order
Citations
PageRank
Mingkun Liu102.37
Lei Guan223.79
Jianqiang Liu307.44
Qingjun Song425.92
Chaofei Ma500.34
Ninghui Li600.34