Abstract:The infrared image generation technology is the core technology for developing infrared imaging target simulators. First of all, the common infrared image generation technologies such as resistor arrays, optical fiber arrays, infrared Cathode Ray Tubes (CRT), Digital Micromirror Devices (DMD) and Liquid Crystal Light Valves (LCLV) are presented in detail. Then, the basic principle and development status of the above five infrared image generation technologies are described. By analyzing and comparing the parameters including the frame frequency, resolution, temperature range, dynamic range and spectral band, it is concluded that the resistor array is the most practical domestic infrared image generation technology at present. Finally, the trend of the domestic resistor arrays is analyzed.

Abstract:The transmission characteristics of terahertz (THz) wave in turbulent atmosphere are very important for the application of THz wave in space. The horizontal transmission characteristics of THz wave in Kolmogorov turbulence atmosphere are studied. The variation of scintillation index and saturated distance of THz plane wave with the frequency, transmission distance and turbulence intensity in turbulent atmosphere is analyzed. Taking the Guassian beam as an example, the variation of the scintillation index and beam width of THz wave beams with the transmission distance in turbulence atmosphere is studied. The results show that in the THz wave band, the higher the frequency of THz wave is, the greater the scintillation index is and the shorter the saturated distance is. In general, when THz wave is transmitting in atmosphere, the influence of turbulence on it is between that on optical wave and that on microwave. For the short-range applications such as communication and imaging, THz wave is mostly in the state of weak fluctuation. But for the long-range applications such as THz radar and imaging, THz wave is in the state of strong fluctuation.

Abstract:Aiming at the problem that the stray radiation in an infrared simulation system may affect the temperature uniformity on the simulated image plane, a conception of temperature difference on an image plane is proposed and a method for calculating the maximum temperature difference on an image plane is given. A simplified infrared simulation system model for calculating the maximum temperature difference on an image plane is established. A partial irradiance deviation factor which can reveal the change of temperature on the image plane is defined. The expression for the above factor and maximum temperature difference on an image plane is deduced. The common steps for calculating the maximum temperature difference on an image plane is also given. The calculation method is demonstrated in a practical infrared simulation system and is verified in an experiment. The results show that the measured temperature differences are all within the theoretical numerical range. So, the correctness and effectiveness of the method are verified.

Abstract:Since target information is easy to be lost or weaken in the current infrared and visible image fusion algorithms, a fusion algorithm based on non-subsampled contourlet transform and an improved pulse coupled neural network is proposed. First, the infrared and visible images which are preprocessed and registered are transformed through non-subsampled contourlet transform and the high-frequency coefficients and low-frequency coefficients of two images are obtained respectively. Then, the improved pulse coupled neural network is used to fuse the high-frequency coefficients of the images and the largest energy in a region is used to deal with the low-frequency coefficients. Finally, the fused coefficients are transformed by using NSCT inverse transform, so as to obtain the fused image. The experimental results show that the proposed algorithm can display more detail information of images in the subjective vision while its several objective data indicators are improved to a different extent.

Abstract:In the precision infrared video data acquisition systems based on TVP5147 and FPGA chips, the video signals are captured by using the Horizontal sync signal (HS), Vertical sync signal (VS), Odd/even field indicator signal (FID) and Active video indicator signal (AVID). This may generally cause the video capture part and video display part to be unable to use the same clock pulse signal, so that video capturing and video displaying can not be synchronized when the video is switched. A method for extracting video signals and clock signals by decoding VPO video data stream is presented. Since the video capture part and video display part can use the same reference clock signal, the problem that capturing and displaying are not synchronized when the video is switched is solved. The method is verified in our self-developed video capture system and good effectiveness is exhibited.

Abstract:When the infrared radiation from a target and its background is not different greatly, the target can not be recognized accurately. To locate the target accurately and destroy it, an idea that a seven-element infrared array is used to scan the target is proposed. The experimental results show that the position of the engine in a target can be recognized accurately by utilizing the infrared characteristics of the target. According to the engine positions in typical targets, the targets can be classified and their critical parts can be recognized and destroyed.