A method for modelling IR images of sky and clouds

Thermal radiation of objects is often used as its discriminative feature by the systems of automatic target recognition (ATR). In such case to develop effective detection algorithms it is essential to know radiation characteristics not only of the detected objects but also its surroundings. The paper presents a method of numerical modelling of clouds radiation in infrared spectral range. The experimental data for the modelling were collected taking into consideration characteristic temperature profiles of the clouds and sky, for particular seasons of the year and meteorological conditions occurring in Poland. Virtual thermal images of sky and clouds were then generated by the specially developed IR Sky software. The images generated by means of this software were analyzed, having in view influence of radiation features of sky and clouds on a thermodetection process. High consistency of computer-generated images with the registered thermal images has been obtained.