Abstract:The magneto-transport characteristics of two classes of HgCdTe materials are analyzed in detail so as to seek out an effective method for screening them. Narrow-gap HgCdTe is a multi-carrier semiconductor system material in which both electrons and holes contribute to conduction. Particularly in the slight n-type HgCdTe material, because the mobility of the electrons is two orders of magnitude greater than that of the holes (b=μe/μh≈10²), it is more likely to be interfered with minority carriers. Therefore, it is impossible to distinguish the low mobility n-type material from the slight p-type with excellent electric properties by using conventional single-field Hall measurements. The magneto-transport characteristics of both HgCdTe materials are measured by using a variable-field Hall measurement method at various temperatures and their differences are analyzed by using a mobility spectrum analysis (MSA) technique. The result shows that the MSA is a technique suitable for distinguishing above both HgCdTe materials.

Abstract:According to the superiority of an infrared search and track system in modern wars, a method for designing a catadioptric infrared optical system is proposed. In the catadioptric infrared optical system, both aberration and second spectrum are corrected by using the same infrared optical material. The design result meets the design requirements and is compatible with the uncooled focal plane array with a pixel size of 25 μm. It can be used in an airborne infrared search and track system.

Abstract:The method and standard for judging overheated components in an electric control cabinet are established according to the related GB in China. The thermal radiation emitted from the overheated components to the inner surface in an electric control cabinet is analyzed according to the infrared radiation theory. The heat flux distribution of the inner surface in the cabinet is obtained and a two-dimensional heat transfer model for the heated cabinet casing is built. On the basis of the infrared imaging temperature measurement data obtained, a L-M algorithm is used to study the inverse heat conduction problem and the heating temperature of the overheated component with different thermal defects in an electric control cabinet is solved accurately. Finally, the severity of the thermal defects of the component in the electric control cabinet is identified by using a surface temperature judgment method. The result shows that the method is useful for the fault diagnosis of the overheated components in electric control cabinets.

Abstract:An adaptive method for correcting the nonuniformity of infrared images and its implementation on FPGA are presented. The method can calculate the correction factor in real time and keep high correction quality. Firstly, a traditional two-point correction method is used to obtain initial correction coefficients. Then, the correction coefficients are modified according to the response characteristics of a focal plane array in real time. Since the modification judgment is added in the coefficient modification, the method overcomes the problems of blurring effect and ghosting. Finally, the method is implemented on the platform of FPGA. The test result shows that the method can meet the real-time and nonuniform requirements and has a good adaptability to environment.

Abstract:An infrared alarm monitor system for communication wells is designed. The system is consisted of diffuse infrared sensors, integrated circuits with digital coding and decoding functions, a special power supply and a LED digital display etc.. When one or some well covers are opened or removed, the infrared receiving module of the monitor system can not receive any diffuse infrared signals. At this moment, the monitor module outputs alarm signal pulses. Then, each corresponding indicator flickers and displays the number of the wells. Because the digital coding technique is incorporated, multiple places can be monitored via one master PC monitor. The whole system adopts a modular structure and has the features of easy light alignment, stable operation and free debug etc.. It has been used in an airport communication network.

Abstract:Traditional temperature measurement algorithms for infrared thermal imagers have a common shortcoming of low measurement accuracy. The temperature values provided by them can not represent the real temperature of an object. In this paper, the temperature measurement principle of an infrared thermal imager is presented. The cause of the above shortcoming is given and the deficiency of the traditional temperature measurement algorithm using blackbody calibration is analyzed. Finally, an accurate temperature measurement algorithm for infrared thermal imagers is proposed. By incorporating the temperature difference look-up table calibration, temperature pretreatment and real temperature conversion into the traditional blackbody calibration algorithm, the new algorithm improves the temperature measurement accuracy of the infrared thermal imager.

Abstract:The medical infrared thermal imaging technology has important applications in both modern medicine and traditional Chinese medicine. To make the physiopathological information of a human body displayed more visually and effectively in an infrared thermal image, the pseudo-color sequence of the color bar in common infrared thermal images is improved and a new color path is designed. In the new color bar, the three components RGB are represented by 13 linear functions. The component R is used to detect the low temperature background and the body edge in image processing. The component G is used to analyze the abnormal high and low temperature areas in the image. The new color bar is not only suitable for the viewing of local focus areas, but also convenient for the whole viewing of the balance of human body temperature distribution. It is helpful to the viewing and analysis of infrared thermal images of a human body.

Abstract:A method for calculating the longest detection range ($L$) of an infrared detector under an ideal condition is presented. The longest detection range ($L$) is closely related to the position of the infrared detector and the altitude of the point object source. Therefore, the military infrared detectors can be classified into three types according to their detection range values. The infrared detectors having the detection range L < 50 km are classified as type I. The infrared detectors having the detection range 50 km ≤ L < 500 km are classified as type II. The infrared detectors having the detection range 500 km ≤ L < 1500 km are classified as type III.

Abstract:According to the features of the infrared image obtained by an imaging anti-ship missile, a method which combines sea-sky-line and coastline detection with target extraction is proposed for the extraction of ship targets. In this method, the digital image processing techniques such as Sobel edge detection and local Hough transform are used to detect the sea-sky-line and coastline in an image. Then, the entropy method introduced by Kapur is used to implement projection transform on the binary image so as to extract the ship target. The experimental result shows that the method can determine the position of a ship target in the sea-sky-line and coastline region and has a higher extraction accuracy.