Abstract:The development of infrared Focal Plane Array (FPA) detectors in format size is a process from sparseness to density and from smallness to largeness. It is limited by the factors such as material growth of large area detectors and fabrication of small pixels. Strategic FPAs are usually used to detect point source targets while tactical FPAs are usually used to detect extended source targets. Starting from the related basic concepts, the evolution of FPA format is analyzed and the relationship between the operation range and the FPA format is discussed. Since TV formats are changeless, the further increase trend of the tactical FPAs in format will be either stopped or slower after their full frame formats are realized. On the other hand, the larger the format of the FPA is, the wider area it can cover each time is. So, the strategic FPAs will develop toward super-large format.

Abstract:To make optical components have their dynamic response as small as possible and meet the required mass specifications, the mass of a space optical remote sensor should be distributed. By establishing a full damping dynamic analysis model for the space optical remote sensor, the expression for the dynamic response of the optical components is obtained. The dynamic amplification characteristics of different dynamic systems are discussed according to the expression. Then, in view of the actual engineering condition, numerical analysis is made via MATLAB programming and the mass distribution condition under which the response of the optical components can be made as small as possible is discussed. The result shows that the optical components have their dynamic response close to the minimum value for a damp ratio of 0.03, a frequency ratio β of 1.3 and a mass ratio of 0.51. Because the method proposed according to the theoretical formula can interpret the result in the formation of chart, it is reliable and easy to use.

Abstract:The geometric calibration of a mapping camera is important in aerial mapping. A mapping camera should be calibrated before it is used. The fundamental principle and method of the geometric calibration of a mapping camera are analyzed. Then, several methods such as the exact angle measurement, PAMC, Tsai's two stage method, Zhang's method, RCA method and self-calibration method are analyzed in particular. Their accuracy and features are given. The result is helpful to the geometric calibration of airborne mapping cameras in different environment.

Abstract:A method for assembling a lens or a lens unit is determined according to the design result and tolerance of an optical system in which an infrared lens is used. The mount and barrel of the lens are designed specially. The center error of the lens unit is measured by an OptiCentric dual-path centrescope. After the lens unit is positioned with pins, each lens unit is reset with pins. When the whole lens unit is assembled, the image quality of the lens is detected in an infrared Modulation Transfer Function (MTF) measurement instrument. The result shows that both the effective focal length and the MTF of the infrared lens unit meet the required specifications and this new dual-path assembling method is reasonable and feasible.

Abstract:Truss structures are widely used in large- and medium-sized remote sensing cameras. The ideal joint for a truss is the hinged one. However, a rigid joint is often used in practical applications. To compare the stiffness and strut material utilization of the trusses using different joints, the bipod structures used commonly in trusses are analyzed firstly. Then, by taking a Serrurier truss as an example, the fundamental frequency of the trusses using two different joints and the maximum stress yielded by the weight of their front frames are calculated in theory. The result shows that the trusses using two different joints have nearly a similar integral stiffness. But in material utilization, the truss using a hinged joint is better than that using a rigid joint. Its strut can save about 21.87% in weight. Finally, the finite element analysis is carried out by using the Nastran software. The analysis result shows that the theoretical calculation is correct and the difference between the two calculation results is less than 1.12%.

Abstract:SF₆ gas may be ionized or decomposed into a variety of gases when discharge or overheat occurs. These decomposed gases can affect the insulation of electric power equipment. However, all of the existing infrared gas detection means can not measure the decomposed SF₆ gas on line in situ. According to the practical needs, an infrared spectrometer system based on the principle of a grating is designed. The system can measure the components and contents of the decomposed SF₆ gas in real time and can operate on line when the electric equipment is in the running state. The measured data provide convincing gist for the analysis of the performance and safety of the electric equipment.

Abstract:Because of the disadvantages of traditional video acquisition devices, such as large volume, simple processing capability and low flexibility, an image acquisition and processing system based on DM642 and CPLD chips is proposed. In the system, the DM642 chip is used to configure a TVP5150 video decoding chip for reading out video image data and processing them. A SAA7121H video coding chip is used to process the data and output them. The CPLD chip is used as the logic controller of the system. The experimental result shows that this system has achieved its desired effectiveness. In the future, the system will be used in the infrared thermal imaging for large space fire detection.

Abstract:Discharging smoke bombs is one of the effective methods to counter laser-guide missiles. To simulate the antagonistic process of smoke jamming, the mathematic models of naval ships, smoke screen and missiles are established, and the jamming evaluation principles are presented. The process of smoke jamming is simulated by programming, and the influence of ship corner, speed of ship and wind speed on the effectiveness of smoke jamming in different counter environment is assessed.

Abstract:In stone detection, the accurate identification of stone types is of great significance to the correct selection of stone. At present, the selection standard of stone is mainly based on the kinds of stone and use experience. When the kinds of stone are difficult to identify, the X-ray Diffraction (XRD) or chemical analysis method is usually used. These methods are subjective or detrimental. A Fourier Transform Infrared (FTIR) spectrometer is used to measure the infrared spectra of stone. Then, the characteristic absorption peaks in the measured infrared spectra are used to identify the types of stone. This method is convenient, fast, accurate and nondestructive. It is helpful to the setting of stone detection standards in the future.