APPLICATION OF THERMAL IMAGE VELOCIMETRY TO URBAN AREA

Thermal Image Velocimetry (TIV) is the method to measure the 2-dimentional wind field tracking the temperature displacement caused by advected turbulent heat exchange using TIR camera. So far, this method has been applied to the surface whose heat capacity is low so as to easily capture the turbulence-caused temperature displacement. We applied TIV to the high-heat-capacity asphalt road within urban canopy for the first time. As a result, we could conduct TIV observation even to the asphalt surface, observing complex wind field within the uraban canopy. Then we need to conduct temporal filtering with larger filter than the cycle of the random noise, which can be estimated by the spectral analysis of the displacement of the surface temperature. Even low performance TIR camera can conduct TIV observation if we set the large temporal filter enough compared to that of high performance TIR camera. And we found the possibility that we can change the size of tracking turbulent structure by changing the filter size,