Impact factors of daytime variation for broadband land surface emissivity of concrete road

Land surface emissivity (LSE) of a material is generally supposed to be a constant. This assumption would result in great errors, when it is used in relevant studies. Too many uncertain factors were involved, when the LSE of materials were measured at the experiment field. Whether the collected LSE is right or not? What's the impact of environmental factors on LSE of materials? And what's the variation model for LSE of materials? In this study, concrete was taken as an example to explore the impact factors of LSE. The on-line measurement data collected by Fluke 576 (infrared and probe temperature) are used to calculate broadband LSE. Diurnal temperature cycle model was introduced to determine the variation trend of LSE in a day. Result indicated that broadband LSE (BLSE) varied with temperature, sun azimuth/elevation, wind speed and the other environmental factors. Further studies are needed for the influence estimation of impact factors on LSE.