Method of calculating land surface temperatures based on the low-altitude UAV thermal infrared remote sensing data and the near-ground meteorological data

Abstract

The continuous urbanization has greatly changed the underlying surfaces, which leads to great impacts on the urban thermal environment. The land surface temperatures (LSTs) have gained considerable attention as a typical indicator for studying the urban thermal environment. Accounting for the deficiency of existing calculation methods in calculation principle of LSTs from the low-altitude thermal infrared remote (TIR) sensing data, this study proposes a method to retrieve the LSTs at a block scale with high temporal and spatial resolution for the effective evaluation of micro urban thermal environment. Thus, the thermal infrared radiation transmission equation is rewritten according to the actual thermal infrared transmission process. The final calculation form of LSTs is given, in which the multi-source data is employed. Ultimately, to verify the accuracy of this method in calculating the LSTs, an application case is designed. The results indicate that the temperature differences between the calculated LSTs and the measured LSTs ranges from -1.73 K to 1.45 K, and the absolute accuracy of the method is 0.09 K based on the correctly obtained multi-source data. This method is available for the quantitative analysis of the urban thermal environment and urban heat island effect at a block scale.