Contents
2021
Volume: 42 Issue 10
7 Article(s)
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Analysis of Infrared Satellite′s Detectability for Common Hypersonic Glide Body
An-hua SHI, Wei-bo SHI, Zhi-gang ZHANG, Jun-hao LIAO, and Sen LIU
With the rapid development of near-space hypersonic technology and the use of near-space hypersonic missiles, new military threats have become a reality. Due to the low flight trajectory of the near-space hypersonic missile and the characteristics of maneuvering flight, it is possible to predict its flight trajectory oWith the rapid development of near-space hypersonic technology and the use of near-space hypersonic missiles, new military threats have become a reality. Due to the low flight trajectory of the near-space hypersonic missile and the characteristics of maneuvering flight, it is possible to predict its flight trajectory only by real-time detection and tracking. Affected by the curvature of the earth and other factors, the detection range of ground-based radar system for near-space hypersonic missile is limited, and there is a huge demand for the number of radars for networking detection, so satellite detection is a better means. The infrared radiation characteristics of the U.S. Navy and Army′s common hypersonic glide body (C-HGB) are analyzed preliminarily. Combined with the detection capabilities of the high-orbit infrared early warning satellite, the detectability of the early warning satellites to the C-HGB in the gliding flight stage is analyzed preliminarily. The results show that the current high-orbit infrared early warning satellites are difficult to detect C-HGB in the gliding phase, so it is necessary to improve the satellite infrared detection system or build a low-orbit satellite constellation..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 10, 1 (2021)
Study on Surface Defect of HgCdTe/CdZnTe(211)B by MBE
Dan WANG, Da GAO, Zhen LI, and Min LIU
The surface defects of HgCdTe material are one of the main reasons for the performance degradation of the detector. Focused ion beam (FIB), scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDX) were used to study the surface defects of the CdZnTe-based HgCdTe epitaxial layer. By analyzing thThe surface defects of HgCdTe material are one of the main reasons for the performance degradation of the detector. Focused ion beam (FIB), scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDX) were used to study the surface defects of the CdZnTe-based HgCdTe epitaxial layer. By analyzing the reasons for the formation of different types of defects, it was determined that the defects originate from the growth process of HgCdTe material. The shape of the defect is closely related to the growth conditions. The microvoid and the volcano-shaped defects are found to be correlated to the Hg deficiency or higher growth temperature. Moreover, the collapse of the material in the molecular beam epitaxy (MBE) effusion cells may cause the instability of the beam flux, which could also contribute to the formation of the above-mentioned defects. Diamond-like defects and diamond-volcano compound defects are related to higher Hg/Te ratio and lower growth temperature. A high-quality HgCdTe epitaxial layer with a composition of 0.216 and a thickness of 6.06--7 μm was grown on the surface of a 5 cm×5 cm CdZnTe(211)B substrate. At the same time, the relationship between the types of defects and the growth process of HgCdTe thin films was established. The research results have reference significance for the preparation of high-quality HgCdTe/CdZnTe epitaxial layers..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 10, 9 (2021)
Simulation Analysis of Optical Transmission Characteristics of Mixed Fe3O4@SiO2 Colloidal Photonic Crystals
Chao-ping WEI, Xiao-xiang WEN, Yu-ting LIU, Xue-gang LU, and Sen YANG
In addition to changing the radius and lattice constant of colloidal photonic crystals to achieve the modulation of photonic bandgap, it is also an important scientific problem that whether the chromogenic behavior can be precisely controlled by the mixing of various size particles. By means of numerical simulation, onIn addition to changing the radius and lattice constant of colloidal photonic crystals to achieve the modulation of photonic bandgap, it is also an important scientific problem that whether the chromogenic behavior can be precisely controlled by the mixing of various size particles. By means of numerical simulation, on the basis of analyzing the dependence of Fe3O4@SiO2 colloidal photonic crystal bandgap range on dielectric constant, electromagnetic wave incidence angle, lattice constant, particle size, and SiO2 coating thickness, the optical transmission characteristics of photonic crystals obtained by mixing particles of varied sizes were studied. The simulation results found that after the magnetic colloidal particles of two particle sizes are mixed at different mass ratios, the photonic bandgap position always falls between the bandgap positions of the photonic crystals formed by the two colloidal particles with different sizes. The reflection spectra gradually shift to red as the doping ratio of the large particle size increases. This result proves that the principle of color mixing is still applicable to colloidal photonic crystals. It has an important reference value for the study of new adjustment methods of colloidal photonic crystal structural color..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 10, 16 (2021)
Influence of the Size of Space Spherical Target on Thermal Effect
Xin-ai BAI
Aiming at “Anti-Simulation Balloon Decoys for Nuclear Warheads”，which is one of the important countermeasures, some specific measures beneficial to penetration are proposed. By means of the thermal network model and difference method, the surface temperature distributions of spherical objects with different sizes in daAiming at “Anti-Simulation Balloon Decoys for Nuclear Warheads”，which is one of the important countermeasures, some specific measures beneficial to penetration are proposed. By means of the thermal network model and difference method, the surface temperature distributions of spherical objects with different sizes in daytime and nighttime are calculated. The results show that in order to make the decoys usable both during the day and at night, a group of different sizes of decoys is designed so that the surface temperature of the decoys is distributed on both sides of the surface temperature of the balloon containing the warhead. This measure can undermine U.S. National Missile Defense (NMD) system′s ability to identify targets based on size and increase the complexity of identifying targets as well..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 10, 24 (2021)
Error Analysis and Correction of Field Temperature Measurement for Portable Infrared Thermal Imager
Ji-jun WANG, Xiao ZHOU, Yan LI, Fang-yuan LI, and Song-lin YU
There are many factors affecting the accuracy of infrared temperature imaging technology. Especially in the complex environment of the experimental field, sometimes it is difficult to reach the expected index. In order to effectively improve the measurement accuracy of portable infrared thermal imager in the field, theThere are many factors affecting the accuracy of infrared temperature imaging technology. Especially in the complex environment of the experimental field, sometimes it is difficult to reach the expected index. In order to effectively improve the measurement accuracy of portable infrared thermal imager in the field, the main influencing factors of the field temperature measurement are sorted and summarized by the infrared temperature measurement theoretical model, and the influence factors are statistically analyzed by using the measured data in the field in the paper. In addition, the corresponding correction method is proposed. The results show that the standard deviation is reduced from 0.89 K to 0.3 K after the correction, which effectively improves the temperature measurement accuracy..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 10, 28 (2021)
Target Extraction Algorithm Based on Variable Threshold and Coordinate Transformation for Infrared Overlapped Fingerprint of Criminal Investigation
Jun-fang LI, Kai-chen LI, and Xiao YU
Infrared overlapped fingerprint image is a kind of complex infrared image in the field of criminal investigation. The information of the image is uncertain，and the fingerprints are overlapped. How to accurately extract the overlapped target is a difficult problem in the field of criminal investigation. To solve this prInfrared overlapped fingerprint image is a kind of complex infrared image in the field of criminal investigation. The information of the image is uncertain，and the fingerprints are overlapped. How to accurately extract the overlapped target is a difficult problem in the field of criminal investigation. To solve this problem, an infrared criminal investigation overlapped fingerprint target extraction algorithm based on the fusion of variable threshold value and coordinate transformation is proposed in this paper. Firstly, the threshold algorithm is used to extract the whole and the overlapped fingerprint image. Then the coordinate transformation method is used to filter the independent regions of the two parts of the images. Finally, the contour fusion algorithm is used to fuse the two parts of the image, so as to obtain the extraction result of the whole fingerprint target. In order to make the extraction results more visual, the coordinate transformation method after the image rotation operation to extract a single fingerprint target is adopted in this paper. Experimental results show that, compared with other target extraction methods, this method has higher accuracy and integrity in the whole and single fingerprint target extraction..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 10, 33 (2021)
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