Contents
2025
Volume: 46 Issue 5
7 Article(s)
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A Review of Monocular Depth Estimation Research
Cheng WANG, Meng-yuan LI, and Chun-ling LI
Monocular depth estimation plays a very important role in many applications such as 3D reconstruction, target tracking, and scene understanding. Since monocular cameras have the characteristics of low cost, widespread equipment, and convenient image acquisition, obtaining depth information from monocular images has becMonocular depth estimation plays a very important role in many applications such as 3D reconstruction, target tracking, and scene understanding. Since monocular cameras have the characteristics of low cost, widespread equipment, and convenient image acquisition, obtaining depth information from monocular images has become a hot research topic. First, the common deep learning models used for monocular depth estimation are summarized, mainly including convolutional neural network (CNN), recurrent neural network (RNN), and generative adversarial network (GAN). Then, the deep learning methods for monocular depth estimation are summarized from the perspective of training methods, and the development trend of monocular depth estimation is summarized..
INFRARED
- Publication Date: Jun. 12, 2025
- Vol. 46, Issue 5, 1 (2025)
Study on Surface Defects of 6-in Short-Wave Silicon-Based HgCdTe Based on Molecular Beam Epitaxy
Zhen LI, Dan WANG, Meng-jia JiIANG, Chong-shang GUAN, Wei-rong XING, Wei-lin SHE, and Jia-jia NIU
Due to the growing demand for large-scale silicon-based HgCdTe materials for large-scale HgCdTe infrared focal plane detectors, the surface macroscopic defect density of 6-in short-wave silicon-based HgCdTe materials based on molecular beam epitaxy (MBE) is studied. The surface defects of the materials are analyzed usiDue to the growing demand for large-scale silicon-based HgCdTe materials for large-scale HgCdTe infrared focal plane detectors, the surface macroscopic defect density of 6-in short-wave silicon-based HgCdTe materials based on molecular beam epitaxy (MBE) is studied. The surface defects of the materials are analyzed using scanning electron microscopy (SEM), and the types of defects and their causes are determined. The composition uniformity of the materials is improved by improving the uniformity of the epitaxial temperature zone, the beam uniformity, and the stability of the source furnace. The preparation technology of 6-in short-wave silicon-based HgCdTe materials based on molecular beam epitaxy is improved by controlling the surface defects of the materials and optimizing the material process parameters, and high-quality 6-in short-wave silicon-based HgCdTe materials with high uniformity and low surface defect density are mass-produced. The results show that the composition difference between the center and the edge of the material is less than or equal to 3.0%, and the surface macroscopic defect (larger than 2 μm) density is less than or equal to 70 cm-2..
INFRARED
- Publication Date: Jun. 12, 2025
- Vol. 46, Issue 5, 11 (2025)
Study on the Particle Cleaning Mechanism of Silicon-Based Infrared Chip After Polishing
Teng-da MA, Sheng-xian XU, Hao-ran LI, Hao SHI, and Hui WANG
The backside polishing quality of silicon-based infrared devices directly affects the performance parameters of the chips, and the cleaning treatment after polishing will also affect the reliability of subsequent processes. Cleaning of particles adsorbed on the surface of materials is a hot topic in current research. TThe backside polishing quality of silicon-based infrared devices directly affects the performance parameters of the chips, and the cleaning treatment after polishing will also affect the reliability of subsequent processes. Cleaning of particles adsorbed on the surface of materials is a hot topic in current research. The cleaning effect of anionic surfactant (sodium dodecyl sulfate (SDS)) on silicon wafer particles after silica sol polishing is explored, and the cleaning mechanism is deeply analyzed using molecular simulation methods. The results show that when the concentration of SDS is high, a bilayer adsorption morphology can be formed on the surface of SiO2 particles, and a negative charge state is presented on the outermost layer. This forms an electrostatic repulsion force with the negative charge on the surface of the silicon wafer in an acidic environment, thereby effectively cleaning the SiO2 particles..
INFRARED
- Publication Date: Jun. 12, 2025
- Vol. 46, Issue 5, 17 (2025)
Experiment and Research on Magnetic Steel Fixing of Stirling Refrigerator Linear Motor
Zhen-lei LI, Qi-chao RAO, and Peng-lei HAN
As an important component of the infrared detector assembly, the fixing method of the linear motor of the Stirling refrigerator is an important factor affecting the reliability of the assembly. If the destructive force of the magnetic steel fixing is higher than 10 kN, the risk of the magnetic steel falling off will beAs an important component of the infrared detector assembly, the fixing method of the linear motor of the Stirling refrigerator is an important factor affecting the reliability of the assembly. If the destructive force of the magnetic steel fixing is higher than 10 kN, the risk of the magnetic steel falling off will be reduced. Therefore, the destructive force of the linear motor of the Stirling refrigerator under different magnetic steel fixing methods is studied. The test results show that in the case of pure gluing or pure welding, the maximum destructive force when the glue is fully applied and one-circle welding is used is close (about 6 kN), and there is a risk of magnetic steel falling off. In the case of combining the two methods, the destructive force when the glue is fully applied and the 6-point welding is used is 11.18 kN, which meets the requirements of magnetic steel fixing; the destructive force when one-circle welding is used is 17.02 kN, which greatly increases the reliability. The simulation data is close to the experimental results, which proves that when the glue is fully applied, the minimum welding condition to avoid the magnetic steel falling off is 6-point welding. When the welding points are less than 6, there is a risk of magnetic steel falling off, causing the refrigerator to hit the cylinder and make an abnormal noise. This result provides a reference for the reliability design of subsequent refrigerators..
INFRARED
- Publication Date: Jun. 12, 2025
- Vol. 46, Issue 5, 24 (2025)
FY-3E/WindRAD Wind Field Products Inspection and Typhoon Adaptability Evaluation
Lin-li CUI, Wei GUO, Jun SHI, and Min-hao CHEN
The satellite-derived ocean surface wind field has important indicative significance and practical value for global typhoon disaster monitoring. The wind field observation data of three ocean buoy stations of the Shanghai Meteorological Bureau and similar satellite products at home and abroad are used to test the accurThe satellite-derived ocean surface wind field has important indicative significance and practical value for global typhoon disaster monitoring. The wind field observation data of three ocean buoy stations of the Shanghai Meteorological Bureau and similar satellite products at home and abroad are used to test the accuracy of the wind field measurement radar (WindRAD) product of Fengyun-3E (FY-3E), and the application capability of the wind field product is evaluated in combination with three typhoons that have affected the Shanghai area during June 2022 and September 2023. The results show that FY-3E/WindRAD can better describe the basic wind circle structure characteristics of typhoons, and compared with the measured results of the buoy stations, the wind speed inversion results of FY-3E/WindRAD basically meet the accuracy requirements of operational applications. Compared with the international similar wind field inversion results, the change law of the typhoon wind circle structure information and maximum wind speed information over time has a good consistency. The research results have important reference value for the application and analysis of FY-3E/WindRAD wind field products..
INFRARED
- Publication Date: Jun. 12, 2025
- Vol. 46, Issue 5, 31 (2025)
Dynamic Monitoring of Water Pollution by Remote Sensing Based on Sentinel-2 Satellite Imagery: A Case Study of Hutuo River in Zhengding County, Shijiazhuang City
Jia-jie LU, Xia ZHANG, Ze-xuan HOU, Zheng-xiong LIAO, Yi-nuo XUE, Meng-ge LI, Jia-qian GUO, Li ZHANG, and Jing-ting YANG
As an important river in Zhengding County, the water pollution situation of Hutuo River affects economic and social development and people′s quality of life. Therefore, it is particularly important to monitor the water pollution situation efficiently. Based on Sentinel-2 satellite imagery, a remote sensing inversion moAs an important river in Zhengding County, the water pollution situation of Hutuo River affects economic and social development and people′s quality of life. Therefore, it is particularly important to monitor the water pollution situation efficiently. Based on Sentinel-2 satellite imagery, a remote sensing inversion model of major water pollutants was constructed by integrating three indicators: chlorophyll-a concentration, suspended matter concentration, and water transparency. The spatial autocorrelation model was used to conduct dynamic remote sensing monitoring of water pollution in the Hutuo River in Zhengding County, Shijiazhuang City. The research results show that during the period from 2019 to 2023, the chlorophyll-a concentration gradually decreased, among which the chlorophyll-a concentration in the upper reaches is the highest in 2019; the area with high suspended matter concentration gradually shifted from the upper reaches to the lower reaches; the water transparency generally showed a trend of first rising and then falling; the degree of water pollution changed from upstream pollution agglomeration to mid- and lower reaches pollution agglomeration; the spatial agglomeration degree of Hutuo River in Zhengding County first decreased and then increased, and the number of high-high agglomeration types continued to decrease, showing a significant spatial negative correlation. By selecting high-precision satellite data and integrating key water pollution indicators, the water pollution status of the Hutuo River is dynamically monitored, revealing the spatial cluster distribution characteristics of water pollution and providing a scientific basis for local water environment protection and governance..
INFRARED
- Publication Date: Jun. 12, 2025
- Vol. 46, Issue 5, 38 (2025)
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