Airborne thermal hyperspectral imaging of urban and rural areas

Airborne thermal infrared (TIR) imaging is often used to study the problematic of urban heat islands (UHI). However, surface temperature measurement using remote sensing techniques often fail to take into account the spectral emissivity of the investigated materials. This leads to mismatches between the true surface temperature and the measured brightness temperature obtained from conventional broadband TIR sensors. Airborne TIR hyperspectral imaging (HSI) was carried out on urban and rural areas at high spectral resolution. The thermodynamic temperature maps obtained upon temperature-emissivity separation (TES) display sharper thermal contrast associated with UHI than their corresponding brightness temperature maps. A chemical map of quartz could also be obtained from the emissivity datacubes. The results illustrate the potential of TIR HSI to address the UHI problematic.