Investigations on the IR-range performance under different atmospheric conditions

摘要

The propagation of IR radiation through the marine boundary layer is very much dependent on atmospheric conditions. Especially the vertical temperature gradient has a strong influence on the maximum detection ranges of an imaging system. Due to the Air-Sea Temperature Difference (ASTD) the distance to the visible horizon can be shorter (ASTD < 0°C) or larger (ASTD > 0°C) than the distance to the geometric horizon. Propagation models exist which predict maximum ranges for varying environmental conditions. FGAN-FOM conducted measurements in the mid and long wave IR (MWIR and LWIR) at different locations. Analysis was made on the signal of IR point sources on board a boat sailing towards the horizon. In this paper measured detection ranges and decreasing and increasing signals with range are compared to model predictions.