8. Application example in the emissive field

In 2003, a major heat wave caused the deaths of tens of thousands of people in France. This phenomenon has a particularly significant impact on the health of urban dwellers, due to the high degree of land artificialisation, which reduces evaporation but increases air temperature close to the ground. This local change in urban climate, known as the urban heat island, is defined as the difference in air temperature between urban and rural areas.

Although remote sensing in the thermal infrared range does not give direct access to air temperature, it does estimate surface temperature, which remains an indicator of this effect. For a good estimate of this parameter, we need to know the emissivity of materials, which can be determined using spectro-imaging.

In the following, an illustration of a surface temperature map is presented, obtained as...