Abstract:In order to meet the requirements of miniaturization of thermal imaging system and different environmental conditions in the electrooptic POD of micro-mini UAV, an uncooled infrared imaging optical system with field of view of 24.5°×19.7° was designed by means of optical passive athermalization, reasonable distribution of focal degrees of lenses with different materials and introduction of a binary optical element. Its operating wavelength range is from 8 m to 12 m， F number is 1.0. The system consists of four lenses with a total weight of only 35 g， and the total length of the optical system is 38 mm. The result shows that the system structure is simple and compact, the back working distance is large, and the imaging quality is high. The modulated transfer function (MTF) value at the cutoff frequency of 30 lp/mm is greater than 0.3, which satisfies the application requirements.

Abstract:With the wide application of airborne electro-optical system, the contradiction between the reliability of engineering application of domestic infrared detector and the localization requirement of core components is becoming more and more obvious. Based on the requirement of airborne electro-optical system, research on application validation process of infrared detectors is conducted, and the application verification method including three stages is formed. It′s applied in an airborne electro-optical long-range detection system. The result shows that the method can effectively exposure risks in advance and release them, laying the theoretical foundation for application validation process design, detailed specifications development and equipment engineering application of imfrared detectors.

Abstract:A correlation model between dynamic test data of infrared characteristics of target and calculation of target operating distance is established theoretically, and a general method of predicting operating distance based on test data is given. As an application, the infrared radiation characteristics of a certain target are dynamically tested by the ground-based large-aperture infrared measurement system in the outfield. The infrared radiation characteristics of the target in both the front and rear directions and the atmospheric transmittance along the tracking path are obtained. The operating distances of different-aperture infrared systems are predicted, and the calculation results are analyzed. The method given here provides a way for researching the prediction of operating distance based on real test data of the target.

Abstract:When the unmanned aerial vehicle (UAV) performs infrared ship target reconnaissance, the detection algorithm has a great influence on the detection accuracy. In order to enhance the detection capability of the UAV′s infrared photoelectric load on the ship''s target, a support vector machine was used to detect the region proposal training algorithm to improve the accuracy of target detection. Region proposal classification data were obtained by training region features in advance. In the detection stage, the region classification data obtained by training was loaded, and the regions which were more likely to contain targets were selected, thereby improving the accuracy of the target detection. In the validation experiment, 368 long-wave infrared images captured by UAV were selected as data sets, and 139 infrared images were selected as test sets. The target detection experiments were carried out using the region proposal training method and non-region proposal training method. The detection results show that the mean accuracy is 14.6% higher when using the region proposal training method than when using the non-region proposal training method.

Abstract:Taking the entire county of Yongqing County, Langfang City, Hebei Province as the research area, the GF1-WFV 16-meter resolution image was used as the data source, and the image data covering multiple phases of the crop growth period was selected to construct the nonralized difference vegetation index (NDVI) time series of the crop. By analyzing the NDVI curve of the study area, it was found that the NDVI time series constructed with the data could describe the growth characteristics of crops in the study area, reflect the phenological differences of different crops in the region, and effectively distinguish the local planting patterns. The decision tree is constructed by selecting characteristic parameters such as the occurrence time of the maximum value, minimum value, peak, peak number and threshold value on the NDVI curve. According to the phenological calendar of the study area and the investigation of the local planting structure, the optimal time phase image was used to classify and extract one or several crops. Decision tree classification and neural network were used respectively, and accuracy verification was carried out to obtain the best crop classification method by comprehensive comparison. The results show that in the county research area of Yongqing County, when the GF1-WFV 16-meter resolution multi-temporal remote sensing data is used for crop classification, the accuracy of decision tree classification and neural network classification are 72.0729% and 87.3%, respectively. The optimal classification is obtained by using decision tree.

Abstract:An epidemiological survey was conducted on the patients with lumbar disc herniation (LDH) based on traditional Chinese medicine (TCM) constitution and infrared thermal imaging technology. The physical and infrared skin temperature distribution characteristics of the population were analyzed and described. A standardized TCM constitution scale was used to discriminate and analyze the constitution types of 243 patients who met the LDH inclusion criteria. Infrared imaging technology was used to observe the distribution of skin temperature in the lumbar sacral projection area and the nerve innervation area of double lower limbs. The LDH population is dominated by the type of physique, accounting for 70.7%. The single constitution accounts for 26.3%. The infrared skin temperature of the LDH population is characterized by a thermal deviation in the middle of the lumbosacral region. The shape is of long strip, flake or small clumps. Infrared skin temperature in the nerve innervation area of double lower limbs shows a cold deviation. The results show that the dominant constitution type of LDH population is Yang deficiency and blood stasis, its infrared skin temperature is regularly distributed. Infrared thermal imaging technology has certain diagnostic value for LDH.