Abstract
Mean Radiant Temperature (MRT) is an important indicator for assessing the thermal environment. Cities have complicated heat and radiation environment, reflecting sunlight/shadow distribution. Thus, for the detailed understanding of the urban heat environment mobile observation of MRT is necessary. Various MRT measurement methods have been proposed: integral radiation measurements (MRT_true), upward/downward radiation measurement with direct solar radiation (MRT_dir), gray globe thermometer with air temperature and wind speed (MRT_gray), and globe anemo-radiometer (MRT_GAR). We carried out the accuracy validation of different methods of MRT measurement in stationary observation and mobile observation. In stationary observation in an open space, accuracy MRT_dir, MRT_gray, and MRT_GAR were 1.32 K, 1.94 K and 5.43 K, in root mean square of error, respectiviry. MRT on globe thermometers had larger fluctuation than other 2 methods. MRT_dir, MRT_gray, and MRT_GAR had a maximum error of 4.1 K, 13.1K and 9.9K, respectiviry. In mobile observation within urban canyon, MRT_gray and MRT_GAR had a maximum error of 13.2 K and 11.5 K, average eroor of 1.2 K and 0.6 K for each point. MRT_GAR can replace MRT_gray because of better accuracy lower cost.
