Publications

Gao, CX; Liu, JX; Ma, HY; Zhao, EY; Wang, RF; Han, QJ; Xu, ZP; Li, W; Duan, SB (2024). An Uncertainty-Based Validation Method for Surface Temperature Products Derived From Sentinel-3/SLSTR Using Ground Measurements. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, 62, 5003320.

Abstract
Surface temperature (ST) is a vital physical parameter influencing surface-atmosphere interactions. This study presents an uncertainty-based validation approach applied to Sentinel-3/Sea and Land Surface Temperature Radiometer (SLSTR) land ST (LST) and sea ST (SST) products. In situ measurements were obtained from various sites in China, namely, the Dunhuang Gobi site (DHGS), Huailai Guanting Reservoir site (HGRS), Wuliangsuhai Lake site (WLSLS), and Yantai Ocean site (YTOS). The spatial representativeness of in situ measurements at each site was assessed using available clear-sky and high-quality Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) LST products from April 2000 to June 2023. The four sites exhibited high spatial homogeneity, demonstrating suitability for validating STs. Therefore, in situ measurements from these homogeneous sites were used to validate the Sentinel-3/SLSTR ST products during the daytime and nighttime using a temperature-based method. The results showed that the root-mean-square error (RMSE) values are lower than 1.6 K, except for those at DHGS. Furthermore, since ground-based ST validation is affected by the coupled effects of surface and atmospheric characteristics, the validation results are different under different atmospheric and surface conditions. Consequently, assessing the consistency among multiple validation results becomes challenging. To address this issue, by assuming the independence of the validation samples, we propose a method for obtaining the key comparison reference value (KCRV) from multiple validation results based on Sentinel-3/SLSTR ST products. The KCRV is close to the true value, indicating the high quality of the validation results. For the Sentinel-3A/SLSTR and Sentinel-3B/SLSTR LST products, the KCRVs are 1.91 and 1.71 K, with corresponding uncertainties of 0.08 and 0.08 K, respectively. Similarly, for the Sentinel-3A/SLSTR and Sentinel-3B/SLSTR SST products, the KCRVs are 0.78 and 0.71 K, with uncertainties of 0.08 and 0.07 K, respectively.

DOI:
10.1109/TGRS.2024.3386178

ISSN:
1558-0644