Measurements of polarization properties of camouflaged objects and of the denial of surfaces covered with cenospheres

Camouflaged objects in a background, which are not possible to observe with conventional IR measurements without polarization, can be seen in polarization measurements. In this paper will be shown that polarization measurements increase the possibility to detect covered objects. The denial of polarization measurements of a covered object has earlier been achieved by construction of a surface covered with cenospheres. The emissivity as a function of angle of incidence has also been investigated on this newly developed surface, which can be designed to have emission properties decided in advance. The results indicate that it is possible to use the surface materiel as a means to adapt an object to a certain optical signature. It has also been shown that the surface almost completely depolarises the emitted radiation, which makes it more difficult to observe with a polarization measurement. These properties make the surface suitable as a reference surface for polarization measurements. A more systematic development of these surfaces and investigation are reported here.