Validation of a model for thermal emission

Abstract

An introduction to the more general aspects of thermal models is followed by a brief outline of the construction and range of possible applications of the computer models-developed at the University of Durham. The physical basis behind one of these models, which predicts temperatures both at the surface and within a one-dimensional non-vegetated object, is considered in some detail, and the construction' of the model is outlined. The sensitivity of the temperature predictions to changes in the values of .the input parameters required by the model are also discussed. Equipment was designed specifically to collect sufficient ground truth data to enable the validation of the model, and there is a complete description of the construction and operation of the apparatus. The subsequent interpretation of the data using the computer is also described. The validation of the model was carried out for two roads with concrete and asphalt surfaces, and consisted of a comparison between surface temperatures predicted by the model and those measured by a radiometer. The results of the comparison are discussed in some detail. The suitability of the model to predict temperature contrasts between two different surfaces was also investigated using the’ validation data. The model was next applied to the more complex problem of simulating the thermal behaviour of a south facing vertical sandstone wall. A comparison between the predictions of the model and data measured by a radiometer is given, and the problems that this type of simulation entails are discussed. A summary is given of the work carried out with the model, and suggestions are made for improvements to the model. Finally, the development of future types of model is considered.