Sea fog is a particular kind of atmospheric aerosol that often poses hidden risks to ship navigation, ocean exploration, human productivity, and life. In light of the aforementioned issues, this research conducted a thorough investigation of the polarization transmission properties in a sea fog environment. We studied the physical characteristics of sea fog and established a polarized radiative transfer model based on RT3/PolRadtran (polarized radiative transfer) in a sea fog environment based on the theory of Mie scattering. The effects of wavelength, polarization state, sea fog concentration, and salt content on the polarization degree were simulated by using the polarization transport model. An indoor sea fog simulation device was designed and built. The simulation test results were compared with the experimental test results from many aspects, and the existing errors were analyzed so that they could be mutually verified for the overall trend. According to the modeling results, distinct polarization states of light exhibit evident depolarization as the sea fog concentration rises. Overall, circularly polarized light has superior polarization-maintaining properties compared to linearly polarized light under the same contrast settings. The penetrating impact of incoming light in the visible range improves with increasing wavelength, and the amount of salt in sea fog has some bearing on the degree of polarization.

The polarised Bidirectional Reflectance Distribution Function (pBRDF) model relates the properties of target materials to the polarisation information of the incident and reflected light. The Priest–Germer (P-G) model was the first strictly pBRDF model to be officially released; however, some shortcomings remain. In this study, we first analyse the assumption framework of the P-G model, analyse the assumption framework to determine the imperfections in the framework, supplement the boundary conditions of the model for diffraction and transmission effects, and propose and construct a polarised pBTDF model based on the existing P-G model and parameter inversion; the output results of the model are compared with the experimental data through simulation. The results show that the intensity relative error and Degree of Linear Polarisation relative error of the target can be reduced by more than 40%, using the improved model, proving its accuracy and precision.

Infrared polarization imaging has demonstrated significant advantages in target detection and recognition in natural environments. While there have been numerous research achievements on medium-wave/long-wave infrared polarization in a single band, there is a lack of related conclusions on the characteristics of wide spectral two-color infrared polarization imaging. To address this gap, this article employs a theoretical model in infrared polarization imaging to investigate the influence of temperature, incident angle, and refractive index on polarization degree and polarization angle. These findings have been substantiated through discussions on experimental results. We conducted a comparative analysis between intensity imaging and polarization imaging within the framework of traditional single-band infrared imaging. We then delineated the benefits of dual-color infrared polarization imaging. Finally, we harnessed image registration fusion algorithms to amalgamate multiple-band images. Our findings demonstrate that this fusion technique not only enables penetration through water mist but also enhances target visibility, providing theoretical support for all-weather target detection and identification.

Researchers in many nations are focusing more on the growth and usage of the marine field, and it is apparent that study on the marine field will be the future development trend. The present study adopts the idea of polarization imaging based on liquid crystal phase retarder as a solution to the drawbacks of conventional industrial camera imaging clarity. Various optical thicknesses are employed to characterize the sea fog concentration; an outside optical imaging equipment is constructed for sea fog imaging research; and pictures comprising polarization characteristics may be determined through image processing. Using multi-band as factors, the benefit of polarization imaging in a sea fog environment is assessed objectively using contrast, information entropy, degree of polarization, and other evaluation indices. The results demonstrate that the quality of the polarization image is superior to that of the intensity image and that the outline of the target is more pronounced in the polarization image. Additionally, the polarization imaging effect is better in the 670 nm band, and the polarization contrast is increased by 1.9%. The contrast trend of the polarization picture is impacted by the time period, but it is roughly equivalent to that of the intensity image. This gives a solid platform for target surveys and civic operations under conditions of dense marine fog.

The concentration of smoke in an environment can cause obvious interference to visible light intensity imaging, and it is a non-negligible factor in the polarized imaging of ground-based targets. Smoke particles cause severe scattering of photon intensity, resulting in polarization. In this case, low-visibility targets can be effectively identified by detecting the polarization dimension of targets. However, the polarization transmission of smoke in an environment is unclear, and the theoretical simulation lacks experimental reliability verification. To study this problem, this study constructs a polarization transmission model in a smoke environment and simulates and analyzes the scattering of visible polarized light at 450, 532, and 671 nm under different smoke densities. The optical thickness is determined to establish a reliable connection between the simulation and the external field long optical path test and verify the transmission of polarized light. Results show that the method has a 60% confidence in the polarization transmission model. With the increase in optical thickness, the degree of polarization (DOP) of the three wavelengths in the visible light band decreases, and the DOP of each polarized light decreases. No obvious difference is found between the DOPs of circularly polarized light at 450 nm and linearly polarized light. The DOP of circularly polarized light at 532 nm is 1–5% higher than that of linearly polarized light, 1–10% higher than that of the outdoor test, 1–5% higher than that of circularly polarized light at 671 nm, and 2–15% higher than that of the outdoor test. Therefore, the shorter the wavelength in the visible band, the higher the DOP. With the increase in wavelength, the polarization characteristics of circularly polarized light are gradually better than those of linearly polarized light.

This paper addresses the objectives in a complex context: the polarization mathematical and physical model of the basic components of the target/background is constructed by simulation modeling. The image fusion experiment is carried out based on a two-dimensional wavelet transformation. A high-resolution polarization imaging instrument was developed, and static experiments were carried out with polarization, infrared, and visible cameras. The result shows that using polarization imaging detection technology to detect physical evidence targets in complex backgrounds can effectively improve target contrast. It can enrich the target information, improve image quality, and improve target detection accuracy.