Combined thermal-LIDAR imagery for urban mapping

Abstract

The use of high resolution thermal imagery to represent the urban thermal landscape provides an excellent method of visualising temperature fields and relating them to real world objects. The mapping of these temperature fields provides data for further analysis and is a powerful mechanism for communicating complex ideas to the general public. Aerial thermal mapping also provides a means of locating areas of heat loss by identifying locations of higher than ambient air temperature. Traditionally, imagery has been displayed in two dimesions; this fails to realistically represent urban landscapes. This paper presents a method of obtaining high resolution thermal imagery from an aerial platform and combining it with existing elevation data for the purposes of mapping the thermal landscape of Christchurch City in 2.5 dimensions. Analysis carried out on the subsequent 2 and 2.5 dimensional maps reveals the complexity of the temperature fields in the urban environment and suggests that surface temperature is not simply a function of received radiation.