Luojia nighttime light data with a 130m spatial resolution providing a better measurement of gridded anthropogenic heat flux than VIIRS

Abstract

Anthropogenic heat flux (AHF) was generally estimated using the nighttime light (NTL) data with a 500 m (NPP-VIIRS) spatial resolution, creating significant uncertainties and distortions. A few studies have attempted to estimate AHF using a 130 m NTL data from the newly launched Luojia 1–01 satellite. However, there is a general lack of work aimed at comparing and validating the advantages of Luojia over its predecessor NTL data on AHF estimation. Therefore, we estimated AHF using Luojia and VIIRS and analyzed the consistency and accuracy of these results by using land cover/land use data. The analysis reveals that VIIRS overestimates the AHF for the natural lands and underestimates the AHF for the urban lands. Compared with VIIRS, Luojia can reduce 1.5–46.9% of AHF overestimations for the natural lands and 13.1–214.9% of AHF underestimations for the urban lands. The analysis also demonstrates that vegetation adjustment is unnecessary to AHF estimation using Luojia NTL data. Besides, the radiance value of Luojia NTL data is more suitable for AHF estimation than other forms (e.g., the digital number value, logarithmic transformation of the radiance value). These results can provide valuable information to improve the understanding of anthropogenic heat and urban thermal environments.