Objective With the continuing development of photoelectric detection technology, infrared polarization technology offers significant advantages, such as cloud penetration and target recognition. Infrared polarization technology has been widely used in stealth, antistealth, and military camouflage. The camouflaged target may be more accurately detected using infrared polarization detection since it shows substantial polarization radiation features in the infrared range. In contrast, coating the surface with a depolarization coating can effectively diminish its polarization characteristics, thereby creating a target camouflage. Therefore, investigating the characteristic polarization modeling of camouflage coatings can aid in the effective generation of camouflage and anticamouflage for the target. Most of the shading functions utilized in the current polarization bidirectional reflectance distribution function (pBRDF) are blind simplified models that do not correspond to the actual rough surface elements. Consequently, it is necessary to conduct shading function research consistent with the real scenario. Research on the polarization characteristics of coatings in the extended infrared band, in particular, is still in its infancy and requires further investigation.Methods In this work, an improved shading function model is adopted, and the specular reflection coefficient and diffuse reflection coefficient are introduced to characterize the polarized radiation characteristics of the camouflage coating surface using the Priest -Germer (P -G) model. A twocomponent pBRDF optimization model is established, and a linear polarization degree model of infrared radiation is derived. The numerical calculation results of the model are compared with the experimental data, and the effects of the surface roughness, geometric attenuation, and diffuse reflection on the infrared polarization degree of the coating surface are analyzed numerically. Additionally, the effect of environmental radiation on the infrared polarization characteristics of the coating is analyzed.
Results and DiscussionsThe numerical results of the proposed infrared polarization model are compared with the experimental data, and the slope of the curve after linear fitting is 0.9924 (Fig. 4). The linear polarization degree model reflecting the geometric attenuation and diffuse reflection effects is analyzed. The results show that the larger the surface roughness of the coating, the smaller the infrared polarization degree (Fig. 6). The more significant the geometric attenuation and diffuse reflection effects, the lower the infrared polarization degree of the coating (Fig. 7). When the ambient radiation ratio is less than 1, that is, when the spontaneous radiation is dominant, the lower the ambient radiation ratio, the higher the degree of linear polarization of the coating. When the ambient radiation ratio is higher than 1, the ambient radiation becomes dominant, and the higher the ratio, the lower the degree of linear polarization of the coating (Fig. 8). When...