Contents
2022
Volume: 43 Issue 9
8 Article(s)
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Research on Design of Airborne High-Resolution Near-Infrared Optical System Based on Optimization of Optical Axis Stability
Qian WANG, Yang LIU, Sai DU, Jing WANG, Tao PENG, Xu YANG, Qiang YAO, Bin PU, Cheng-bo FAN, and De-sheng WANG
In view of the photoelectric system of some high-altitude fighter aircraft with high requirement of optical axis stability, several elements to improve the stability of optical axis in the design of optical system are analyzed, and the condition of heat dissipation formula is given in this paper. The formula of depth oIn view of the photoelectric system of some high-altitude fighter aircraft with high requirement of optical axis stability, several elements to improve the stability of optical axis in the design of optical system are analyzed, and the condition of heat dissipation formula is given in this paper. The formula of depth of field is deduced, and four ways to improve the stability of optical axis are obtained. The design of optical full passive compensation without heating in large temperature range, the reduction of tolerance sensitivity, the improvement of stiffness and strength of structural parts and the use of field depth focusing mechanism meet the requirements of airborne high and low space use with large working distance. In addition, the design idea of a miniaturized airborne NIR athermal zoom system is introduced. The optical compensation and four lens groups are used in the system. The last group is the depth-of-field focusing mechanism. The system has good image quality, loose tolerance characteristics and good optical axis stability in the temperature range from -55℃ to 70℃..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 9, 1 (2022)
Research on Back-Thinning Technology for Type-II Superlattice Infrared Detector
Chun-ling LI, Xue FENG, Wei-rong XING, Tao WEN, and Peng ZHOU
In order to verify the correctness of the epitaxial material preparation process test, reduce the absorption of infrared light by the GaSb substrate, and at the same time improve the reliability and long-term stability of the detector, the GaSb substrate of the type-II superlattice infrared detector needs to be thinnedIn order to verify the correctness of the epitaxial material preparation process test, reduce the absorption of infrared light by the GaSb substrate, and at the same time improve the reliability and long-term stability of the detector, the GaSb substrate of the type-II superlattice infrared detector needs to be thinned. The backside of the GaSb substrate of the type-II superlattice detector is thinned by mechanical polishing and chemical mechanical polishing. Finally, the GaSb substrate is completely removed by etching with a special etching liquid, and the type-II superlattice material is completely exposed. Scanning electron microscope experiment shows that the barrier layer of the superlattice material can play a good blocking role, the surface of the material is smooth, and the substrate has no residue. The detector performance test results show that the performance of the thinned detector chip does not change..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 9, 10 (2022)
Effect of the Getter Repeated Activation Times on the Intake Performance
Chen YUE, Jie YAN, Zhi-kai FU, and Guan WANG
The vacuum reliability of the infrared detector dewar is of great significance to the normal operation of the dewar. The long-term vacuum reliability of the dewar is at risk if the intake capability decreases after getter activation. By testing the effect of repeated activation times of ZrVFe getter in a vacuum environThe vacuum reliability of the infrared detector dewar is of great significance to the normal operation of the dewar. The long-term vacuum reliability of the dewar is at risk if the intake capability decreases after getter activation. By testing the effect of repeated activation times of ZrVFe getter in a vacuum environment on the intake performance, the corresponding data on the change of the intake amount and the inhalation rate were obtained. The results show that with the increase of the repeated activation times of the getter, the total amount of saturated inhalation has no obvious change, the initial inhalation rate increases slightly, and finally tends to be stable. The experimental results can be used to guide the subsequent dewar packaging process..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 9, 15 (2022)
Research on Structure Design of Fiber Grating Vibration Sensor
Zhen-an JIA, Shuo DANG, Da-kuan YU, Jie REN, and Li-rong JIANG
Sensing technology is an important symbol to measure the degree of informatization of a country. The detection of vibration signals plays an important role in industry, especially in the exploration of oil. The vibration sensor based on fiber Bragg grating (FBG) has attracted much attention because it has many advantagSensing technology is an important symbol to measure the degree of informatization of a country. The detection of vibration signals plays an important role in industry, especially in the exploration of oil. The vibration sensor based on fiber Bragg grating (FBG) has attracted much attention because it has many advantages. In this paper, the principle of fiber Bragg grating vibration sensor is briefly introduced, and the FBG vibration sensor developed in recent years is classified and summarized according to its structure type. The advantages and disadvantages of four kinds of FBG vibration sensors are described, and the FBG vibration sensors with cantilever beam and flexure hinge structure are summarized. The existing FBG vibration sensors are analyzed from three directions and optimization suggestions are put forward. Finally, the development of FBG vibration sensors is predicted and prospected..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 9, 20 (2022)
Intelligent Detection of Specific Target Based on Infrared Sequence Images
Chen-hong SUN, Xiao-tian YANG, and Liang WANG
Infrared imaging detection technology is an important technology that military operations need to rely on at present and in the future. In this paper, satellite infrared remote sensing image is taken as the processing object, and artificial intelligence related technology is used to detect the target of image data. BasInfrared imaging detection technology is an important technology that military operations need to rely on at present and in the future. In this paper, satellite infrared remote sensing image is taken as the processing object, and artificial intelligence related technology is used to detect the target of image data. Based on the correlation analysis of the specific target detected in the sequence image, the trajectory report of the specific target is generated according to the extracted gray scale and motion change information of the target. The experimental results show that the average accuracy rate of multi-target detection is 90%, which can reach 95% in some scenes, and the error detection rate is 7%. The average accuracy of multi-target tracking is 91%, and the error detection rate is 6%. They provide information support for timely detection and early warning of specific targets..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 9, 28 (2022)
Research on Inversion of Convective Cloud Top Height Based on Infrared Brightness Temperature Method
Lian DUAN, Yang ZHANG, Peng-yu GUO, and Zhi ZHAO
The AHI data of Himawari-8 and the infrared brightness temperature method are used to calculate the height of convective cloud tops in the 20°N--30°N and 100°E--120°E regions from June to August in 2019. Firstly, the convective cloud region is selected by threshold method. Then, based on the infrareThe AHI data of Himawari-8 and the infrared brightness temperature method are used to calculate the height of convective cloud tops in the 20°N--30°N and 100°E--120°E regions from June to August in 2019. Firstly, the convective cloud region is selected by threshold method. Then, based on the infrared brightness temperature method, the cloud top height is retrieved using the 112m channel data of Himawari-8 and the temperature pressure layer data of ERA5 reanalysis data. Finally, the retrieved cloud top height is compared with the product data of GPM. The results show that the convective cloud top heights inverted from the Himawari-8 data by the infrared brightness temperature method are consistent with the GPM product data, and have a good correlation. The correlation coefficient is 09, RMSD is 029, and the mean deviation is 048. The discrete distribution of the latitudinal direction is better than that of the meridional direction, which has strong applicability..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 9, 33 (2022)
Research on Bridge Monitoring Experiment Based on Brillouin Optical Frequency Domain Analysis Technology
Chuan-wei DU, Tao HU, Ming YUAN, Qiang HAN, Ye-hong LI, and Jia-yu WANG
Brillouin optical frequency domain analysis (BOFDA) is a kind of distributed fiber sensing technology. In this paper, the development history of BOFDA is reviewed, and the latest application progress of BOFDA is introduced. A new method of measuring bridge deflection based on BOFDA is proposed as well. Firstly, throughBrillouin optical frequency domain analysis (BOFDA) is a kind of distributed fiber sensing technology. In this paper, the development history of BOFDA is reviewed, and the latest application progress of BOFDA is introduced. A new method of measuring bridge deflection based on BOFDA is proposed as well. Firstly, through the study of optical fiber layout, it is proposed that the optical fiber is laid on the bottom of the bridge in a comprehensive pasting way. Then the theory of optical fiber strain characterizing the bridge deflection is analyzed. Finally, the experimental study of indoor bridge model measurement based on BOFDA is carried out. The experimental results show that the deflection of the bridge model measured by the dial indicator is in direct proportion to the graded concentrated load on the bridge model and the fiber strain on the lower surface of the model. The deformation range of the bridge model can be calibrated by BOFDA fiber strain, and the deflection of the bridge model characterized by fiber strain is basically consistent with the deflection measured by the dial indicator. Therefore, it is feasible to use BOFDA technology for bridge deflection measurement..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 9, 41 (2022)
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