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Luoyang Henan, China

Li H.,63880 Army Unit | Li H.,National University of Defense Technology | Qin S.,National University of Defense Technology | Wei W.,National University of Defense Technology | Huang C.,63880 Army Unit
Guangxue Jishu/Optical Technique

The process analysis of the two-order dynamic response of Laser Target Designators (LTD) and the aiming errors are introduced in the Air-borne platform LTD random position jittering simulation. The Gauss white noises and the filtered colored noises are used to simulate the dynamic statistical characters of LTD jittering facula's time-response position and diffuse reflected energy under the simplified model of targets, together with the test results of the two different kinds of materials. The analysis shows that the dynamic diffuse reflected energy is related to the movement between platform and targets, the target's surface diffuse reflection characters and surface reflection characters. The method and the results can be used in the dynamic simulation of LTD signals' atmosphere propagation and detection. Source

Che J.,63880 Army Unit | Xu X.,National University of Defense Technology | Zhang H.,63880 Army Unit | Zhao W.,63880 Army Unit | Cheng B.,63880 Army Unit
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering

The large area concentric circles ring laser flare was discovered when CO2 laser interfered infrared imaging system. According to the shape of laser flare, the formation conditions were considerated synthetically, such as equal thickness interference, the shape of equal thickness interference fringes, the optical system structure of infrared imaging system, the aperture structure of infrared imaging system, the diffraction fringes shape of optical components in the event of damage, the spot shape of circular hole diffraction, the thermal effects of CO2 laser and other factors. The causes were analyzed from the aspects of interference, diffraction and infrared imaging system's aperture secondary imaging, and parts of the causes were analyzed and validated by experiment and simulation. The results indicate that the laser flare is Newton's rings, which is formed from equal thickness interference after the lens array of infrared imaging system is irradiated by laser time after time. Source

Che J.,63880 Army Unit | Li Z.,63880 Army Unit | Zhang J.,63880 Army Unit
Proceedings of SPIE - The International Society for Optical Engineering

The low-light level night-vision device was widely applied in military and common field. The working principle of the low-light level night-vision device and radiation shine mechanism of highlight interference bomb were analysed. The tactical use way of the highlight interference bomb was briefly analysed. In addition, the computing method of flash radiation was provided. The jamming mechanism for intense light bomb by antagonizing low-light level night-vision device was analysed from the relation between surroundings illuminate and luminance of fluorescent screen, the relation between target illuminate and damage threshold of fluorescent screen and the influence on lifetime of instrument by intense light, which provided reference to study the jamming technology on the low-light level night-vision device. © 2013 SPIE. Source

Che J.,63880 Army Unit | Wang D.,63880 Army Unit | Zhang H.,63880 Army Unit | Zhang L.,63880 Army Unit | Dong Z.,63880 Army Unit
Proceedings of SPIE - The International Society for Optical Engineering

In order to study the saturation threshold and the image jamming effect of wavelength, energy or power, frequency and size of laser spot, the laser saturation jamming experiments by means of diffuseness are developed, in which, CO2 tunable pulse laser and CO2 continuous wave(CW) laser separately interfere HgCdTe 288x4 cooled scanning IR imaging system and microbolometer poly-Si 320x240 Uncooled Focal Plane Array(UFPA) staring IR imaging system. The jamming effect is reflected through the output-images of the IR imaging system. Therefore, when the experiments were developing, with the minishing of the laser beam attenuation, the energy or power density of the laser was augmented. Simultaneously, with the density of laser spot changing, the changes of output-images had also taken place. The output-images of the IR imaging system were also observed, collected and saved. Moreover, by adjusting the laser's energy density, the saturation threshold was tested. Furthermore, by adjusting the laser's energy or power density, wavelength, frequency and size of laser spot, the image jamming effect of IR imaging system induced by CO 2 laser was studied. In the experiments of the size of laser spot's to jamming effect, on the premise of the laser energy being invariable, with the laser spot enlarging, on the contribution to jamming effect, the added interfered image elements compensate the loss to jamming effect due to energy descending and exceed it. In the experiments of the frequency to jamming effect, when the jamming laser works with higher repeating frequency, after the interference is stopped, the resume time of IR imaging system is more than it of laser working with monopulse interference. Within settled time, much impulses engender accumulation of energy in detector, which correspond to improving the laser's intensity at the jamming effect angle. So, the jamming effect of IR image system is rightly proportional to intensity of interference laser. And improving jamming laser's frequency is propitious to jamming effect of IR image system. In the experiments of CO2 tunable pulse laser interfering HgCdTe 288x4 cooled scanning IR imaging system, the jamming effect of pulse laser is unconspicuous. On the contrary, the CW laser's jamming effect is conspicuous. This also have something to do with the responding wave band of IR imaging system. The all results are analyzed through analyzing the jamming images, and they show that the jamming effects are improved with energy, frequency, wavelength and size of laser spot increasing. Otherwise, the jamming effect proves that the jamming means of diffuseness is feasible. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE). Source

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