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Abstract:

Abstract:The underwater acoustic signal can cause surface wave motion at the water-air interface and hence modulate the magnitude of the laser beam falling on the water surface.The modulated underwater laser signal can be detected by using a direct light intensity detection method.In this paper,the feasibility of the laser detection of underwater acoustic signals is verified on the basis of theoretical analysis.

Abstract:In this paper, a method for measuring the field of view of an infrared thermistor sensor, the principle of hardware, the software design method and the algorithm for auto-mearsurement are presented. The parallel light from different incoming angles is focused at different points of the sensitive element by a lens. The signals of corresponding intensity are obtained. Through frequency selection, amplification, data acquisition and data processing by the measurement system, the envelope curved surface of signal intensity and the curve of the field of view close to the ideal theoretical design value are obtained. Thus, the quality of the sensor can be evaluated and the errors caused by the deviation between the boresight of the lens and the mechanical axes of the sensor can be corrected.

Abstract:After adopting IR stealth techniques,the IR radiation of objects can be depressed and their probability to be detected can also be reduced.In this paper,the objects' probability to be detected before and after the adoption of infrared stealth techniques are compared and the efficiency of the infrared stealth techniques are analyzed through the calculation of the signal-to-noise ratio and the probability to be detected at different distances.

Abstract:In this paper,a special velocity vibration test is designed to simulate the operating envi- ronment of the rotating mechanism of COCTS;The vibration characteristics of the stepping motor are discussed;and a dynamic model of the stepping motor velocity vibration environment is eatablished. According to this model,the numerical emulation is done by using different parameters.The results have indicated that the operation state of the stepping motor can be abnormal under the velocity vibration condition.

Abstract:本文介绍了基于干涉法和光谱吸收法的光纤甲烷气体传感器系统的原理、设计和系统结构,并对它们进行了比较.采用光学测量方法,不仅能精确测量甲烷气体浓度,而且安全可靠.尤其在1.6654 μm波长处,采用光谱吸收法测量甲烷气体浓度,可使传感系统的灵敏度变得更高.

Abstract:Over the last ten years, the application of fractal transform has become one of the hot problems in the realm of image compression techniques. Theoretically, the compression ratio of the fractal transform can be several orders of magnitude higher than that of the classic compression method. However, in fact, the original images can often be polluted by noise. The existence of noise can not only cause the image coding time to be prolonged, but also cause the signal-to-noise ratio of images to be reduced and hence cause the image quality to be decreased apparently. In this paper, the principle and characteristics of wavelet transform and fractal compression coding are analyzed. The method for fractal image noise reduction and compression based on wavelet are studied by using the fractal self-similarity. The method can effectively reduce the calculation complexity and coding time and obtain good image quality. The experimental results have shown that good compression results can be obtained by this method in the case of large compression ratio and the potential of the method is apparent.

Abstract:A typical structural model and a coupled equation group of a one-order Raman fiber optical laser using P-doped optical fiber as its gain medium are presented. The simulation and analysis are carried out by using a numerical method. On the basis of the above simulation and analysis, the influence of fiber length, output mirror relectivity, pump power and etc on the output power and thrshold are analyzed and compared. Finally, an optimized design is given.

Abstract:Under the traditional conditions, we can not make direct measurement on the electric equipment and hence can not find the overheating phenomenon in it. The infrared thermographer can detect the failures in electric equipment through temperature measurement. In this paper, the principle and features of infrared online inspection are maily discussed and inspection examples, result analysis and common inspection methods are presented.

Abstract:第三代红外成像技术需要高性能的大规格红外焦平面列阵.HgCdTe红外焦平面列阵所呈现的性能可满足这种要求.基于硅的复合衬底已被证明是实现高分辨率HgCdTe列阵的首选衬底.复合衬底的工艺技术具有可量测性,目前使用的衬底尺寸已达6in,而且具有极好的组分均匀性.代表目前工艺水平的复合衬底所呈现的位错密度处于中低档范围,即105cm-2.然而,在复合衬底上生长的HgCdTe外延层所呈现的缺陷密度为106cm-2.最近在CdSeTe/Si复合衬底方面的研制工作表明,这种衬底很有希望与HgCdTe合金达到更好的晶

Abstract:一、图像融合 1.利用主成分分析对压缩数据投影限幅图像进行融合(V.R.Riasati,美国科学应用国际公司) 2.实时执行图像的配准和融合(D.J.Dwyer,英国Octec公司)