Abstract:The large field-of-view optical passive athermalization system realized by using ordinary infrared optical materials has a technical problem that the number of lenses is large, and it is difficult to realize the lightweight and miniaturization when this system is applied to the current new high-resolution, large-area-array infrared detectors. To this end, a chalcogenide glass with a low temperature coefficient of refractive index is introduced, and an optical passive athermalization imaging optical system with a working band of 8－12 μm, a field-of-view of 40°×32.5°, an F-number of 1.0, and a 1280×1024 detector are designed. The design results show that in the operating temperature range of -55－70℃, the modulation transfer function (MTF) values at the detector characteristic frequency of 42 1p/mm are all greater than 0.35. The imaging performance of the system is good, which can meet the requirements of practical engineering applications.

Abstract:Aiming at the contradiction between data processing capacity and real-time performance in current low-light-level video image acquisition and processing system, a real-time signal acquisition and preprocessing system based on FPGA is designed. The high-performance Xilinx A7 series chip is used as the main control chip. Two DDR2 SDRAM are used as the core memory device. And a CMOS sensing lens is customized as the video image acquisition device. When the hardware design of the system is completed, the engineering design and simulation analysis of the software system are carried out by Xilinx Vivado platform and Matlab. The whole process of video image acquisition, storage, processing and display in the low-light-level environment is realized. The experimental results show that the low-light-level video images acquired by the system have good real-time performance and smooth dynamic pictures.

Abstract:The cleaning process of InSb infrared detector before passivation was studied. On the basis of traditional cleaning method, a special cleaning solution was added to optimize the surface quality of InSb material before passivation. TOF-SIMS spectrometry test result showed that the Si impurity concentration on the surface of InSb material was reduced by about 85%, the concentration of main organic impurities was reduced by about 30%－60%, and the overall impurity content on the surface was significantly reduced after adding special cleaning solution. It is verified by tape-out that adding special cleaning solution for surface cleaning before passivation can improve the I-V performance and the long-term reliability of InSb photovoltaic chip significantly. This indicates that the surface quality of InSb material before passivation has an important influence on the performance and reliability of InSb infrared detectors. The optimization direction of cleaning before passivation provided in this paper has certain guiding significance.

Abstract:Functional textile materials with low infrared emissivity and heat insulation are widely used in industrial and military fields. In this paper, the functional materials with low infrared emissivity and good heat insulation performance are prepared from the two aspects of low surface emissivity and controlling the surface temperature of objects. The effects of particle size and dosage of aluminum powder on infrared emissivity of coating are studied by using PA as film forming bonding material. Different hollow microbeads are used as thermal insulation filler, and the thermal insulation effect of coated fabric is studied. Finally, the low emissivity coating and heat insulation coating are combined to produce a material with low emissivity and heat insulation properties. The results show that the emissivity of 400 mesh sheet aluminum powder is lower than that of 600 mesh sheet aluminum powder. The infrared emissivity of the coating surface prepared by 20% 400 mesh sheet aluminum powder coating adhesive is as low as 0.237. Since hollow microbeads are good thermal insulation fillers, 15% glass microbeads are used as thermal insulation layer, and 20% 400 mesh flake aluminum powder is used as infrared low emissivity coating. The emissivity of the prepared fiber-based composite coating material is 0.507, and the temperature difference between the hot body sample and the background is 3.75℃. The material has good thermal insulation performance and low infrared emissivity.

Abstract:Aiming at the problem of low accuracy of traditional infrared image target classification methods, a method of SVM based on PSO combined with multi-feature fusion is proposed. HOG and LBP are used to describe the contour features and local textures of targets in infrared images. The method shows the characteristics of infrared image from different aspects, so there is a certain complementarity in the expression of image features. After feature extraction, the convex hull algorithm is used to calculate the sample data, and some representative sample data are obtained, so as to improve the efficiency of classification calculation. In the training of classification model, PSO is used to optimize SVM to find the optimal penalty factor and kernel parameters of SVM, so as to improve the accuracy of classification model. The experimental results show that the accuracy of the multi-feature fusion classification model is nearly 10% higher than that of the single-feature classification model, and the classification accuracy of the final SVM model optimized by PSO is as high as 99%.

Abstract:In 2019, the CO2M mission has been selected by the ESA as Sentinel 7 in Copernicus programme, which will be measuring CO₂ concentration in terms of column-averaged mole fraction (denoted as XCO₂). The payload comprises a suite of instruments addressing the various aspects of the challenging observation requirements. A push-broom imaging spectrometer will perform co-located measurements of top-of-atmosphere radiances in the near infrared (NIR) and short-wave infrared (SWIR) at high to moderate spectral resolution. A multi-angle polarimeter is co-located measurements of aerosols performed. Finally, measurements of a three-band cloud imager, co-registered with the CO₂ observations, will provide the required cloud-flagging capacity at sub-sample level. This paper will review the results of the Phase A/B1 instrument studies, including technology pre-development activities, preliminary design of the CO2M mission′s instruments, etc.