Ground and top of canopy layer urban heat island partitioning on an airborne image

Analyzing the urban heat island from remote sensing thermal images does not distinguish between the various urban levels, i.e., between ground and the top of the urban canopy layer (roofs surfaces). Applying image processing techniques for roofs/ground partitioning and analyzing these levels separately by DISTCORMAT spatial technique reveals that the heat island centers do not coincide. The distance between these centers on a nocturnal image of Johannesburg (South Africa) may reach more than 300 m.