The surface of a complex material with a periodic structure is equivalent to the surface of a uniform material, and the measurement and data processing methods for the equivalent optical BRDF of a solar panel based on a large-scale spot are proposed. Based on a solar simulator, high-intensity light illuminometer, low-intensity light illuminometer and precise rotary platform, the BRDF automatic measurement platform is built. Spot size optimization and a measurement radius optimization method are proposed. The measurement results show that the BRDF of the solar panel has specular reflection characteristics, but that it still differs from the solar cell in the half width of the BRDF curve. Measurement error analysis is performed for the measurement process; its value is 6.74%. The measurement results can be used to improve the understanding of the optical reflection characteristics of the solar panel. Meanwhile, the method can also be used to measure and characterize the coatings of heat insulation material and scattering coating. The measurement data also has practical reference value for evaluations of improvements of the light absorption of the surface functional material. Finally, it can be used to simulate the target image scene.

Ship detection in optical remote sensing images plays a vital role in numerous civil and military applications, encompassing maritime rescue, port management and sea area surveillance. However, the multi-scale and deformation characteristics of ships in remote sensing images, as well as complex scene interferences such as varying degrees of clouds, obvious shadows, and complex port facilities, pose challenges for ship detection performance. To address these problems, we propose a novel ship detection method by combining multi-scale deformation modeling and fine region highlight-based loss function. First, a visual saliency extraction network based on multiple receptive field and deformable convolution is proposed, which employs multiple receptive fields to mine the difference between the target and the background, and accurately extracts the complete features of the target through deformable convolution, thus improving the ability to distinguish the target from the complex background. Then, a customized loss function for the fine target region highlight is employed, which comprehensively considers the brightness, contrast and structural characteristics of ship targets, thus improving the classification performance in complex scenes with interferences. The experimental results on a high-quality ship dataset indicate that our method realizes state-of-the-art performance compared to eleven considered detection models.

The predecessor of China Optics was China Optics and Applied Optics Digest, which was founded in 1985. At that time, it was the only retrieval journal in the field of optics in China. At the end of 2008, China Optics and Applied Optics Digest was renamed 《中国光学》的前身是1985年创办的《中国光学与应用光学文摘》，当时是国内光学领域唯一的检索刊物。2008年底《中国光学与应用光学文摘》转型更名为《中国光学与应用光学》期刊，刊载内容突破了文摘的限制，正式成为学术刊物。

The purpose of this paper is to establish a diffraction Bidirectional Reflection Distribution Function (BRDF) model of surface defects including scratches and pits, and to analyze the model being applied in various fields. By using nonparaxial scalar diffraction theory, a coherent window function filtering method is proposed, which can obtain the BRDF model of surface defect diffraction under incoherent light conditions. The effectiveness of the model is verified in related work, and the scattering characteristics of surface scratches and pits are obtained. The method and the results obtained by the model have high value in surface defect detection, surface defect stray light analysis and image rendering technology.

This study presents a near‐domain‐based diagnosis algorithm for wireless sensor networks nodes. The whole network is clustered to adapt to dynamic topologies, then self‐diagnosis procedure is started simultaneously on all nodes when a new cycle is initiated, or an abnormal behaviour is detected. Matching with neighbour nodes at most twice, the status of a node can be diagnosed. Wireless link fault between nodes is particularly considered in this study which may lead to the erroneous diagnosis of node status. Theoretical analysis and simulation results show that the proposed method has a high accuracy of fault diagnosis and a less communication traffic between nodes, thus greatly reducing energy consumption. At the same time, a high robustness is maintained in this novel fault diagnosis algorithm.