共查询到16条相似文献,搜索用时 62 毫秒
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《红外技术》2017,(10):873-879
高性能InP/InGaAs宽光谱探测器将前截止波长延伸到0.9mm之前,实现可见/短波双波段探测,大大丰富了探测目标的信息量,提高对目标的识别率。本文采用InP/InGaAs宽光谱探测器相机,通过设置一系列伪装实验,对比不同伪装目标的可见光波图像与短波红外图像的差异,重点探究短波红外对伪装目标的识别特性。通过实验结果发现:短波红外对一定厚度塑料、硅胶、皮肤具有穿透性;颜料、染料等同色不同材质的物体对短波红外具有选择性吸收,基于以上特性,短波红外体现了较好的伪装识别效果。在成像对比实验的基础上,进一步选择伪装效果对可见光和短波红外具有明显差异的实验样品,分别测量了它们对短波红外和可见光的反射率等参数,以深入地分析和理解短波红外识别伪装的机理。 相似文献
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雾对光波的作用机理探讨 总被引:2,自引:1,他引:1
由于电磁辐射与介质相互作用的散射原理,从而影响了光波传输.简要计算分析了雾的消光性能及水雾对光波的衰减作用,运用了米氏散射公式和朗伯-比尔定律及对应的相关曲线,分析了水雾对可见羌、红外、激光传输的影响. 相似文献
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为满足信息化作战条件下多频谱兼容伪装的需求,采用多种材料合理匹配与多功能层结构组合的方法,研制了一种可见光、红外和雷达多频谱兼容的新型仿形复合伪装材料,研究了吸波材料中碳含量与铁含量的质量比对雷达波吸波性能的影响。采用雷达波屏蔽效能和反射率实验测试了伪装材料的吸波性能,采用成像法检测了伪装材料的可见光和热红外伪装性能。结果表明,当吸波材料中碳含量与铁含量的质量比为1∶2时,伪装材料的雷达波衰减性能最好,大于5 dB的吸收频宽最高可达4.7 GHz。研制的仿形伪装材料的表面纹理、颜色、亮度、热图与背景环境较为接近,隔热效果较好,具有良好的可见光和红外伪装效果。 相似文献
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水雾对红外光谱遮蔽衰减特性研究 总被引:3,自引:1,他引:2
从理论上简要阐述了水雾对红外光谱的遮蔽衰减特性,用朗伯—比尔定律描述、分析了红外光谱在辐射传输过程中辐射经水雾吸收和散射后的能量变化.同时用米氏散射理论解释、计算水雾粒子的散射系数、消光系数并考虑路径辐射过程其他因素的影响.并且通过检测评估说明了水雾对红外辐射能量的遮蔽衰减特性. 相似文献
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人工水雾对热辐射有着强烈的散射和吸收,可用于火灾安全和红外隐身。将水雾视为吸收、各向异性散射的灰体介质,考虑水雾的介质辐射、多重散射和环境的影响,利用窄谱带模型和Mie散射理论计算离散谱带的平均光学系数,将辐射传输方程和能量守恒方程耦合计算,建立了8~14微米红外辐射在水雾中衰减的计算模型。应用蒙特卡洛法与本文算法作对比,验证了模型的正确性;计算分析了目标在水雾遮蔽下的辐射强度场、热流密度散度以及对水雾温度场的影响;利用本文模型计算了光谱半球通过率,通过与朗伯比尔定律作对比,反映了介质辐射、多重散射、辐射热流等因素使得水雾遮蔽效率降低。 相似文献
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水雾在舰艇防御光学制导导弹中的应用 总被引:4,自引:0,他引:4
利用水雾发生装置在极短的时间内形成大面积、高密度水雾,对敌红外点源制导、红外成像制导、电视成像制导导弹产生有效的干扰作用以保护水面舰艇。分析了水雾的干扰机理,介绍了发生装置,讨论了形成水雾的时机。 相似文献
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基于gamma雾滴尺寸分布模型及辐射雾和平流雾含水量与能见度的经验关系,计算并回归得到了平流雾和辐射雾对10.6μm红外辐射的衰减与含水量和能见度的关系,其对浓辐射雾得到的雾衰减与含水量的线性关系与文献所给实验结果和半经验公式均有很好的一致性.最后对雾的红外衰减和可见光衰减进行了比较,结果表明浓平流雾对10.6μm红外辐射的雾衰减大于可见光的雾衰减. 相似文献
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通过试验研究了1.06 m激光辐射在水雾环境中的衰减特性。定量测量了不同气象光学视程(MOR)的水雾对1.06 m激光辐射的衰减程度,计算了水雾环境下的1.06 m激光辐射的等效MOR。分别采用试验数据和经验公式计算了1.06 m激光辐射在不同能见度条件下的消光系数。通过对比发现由经验公式计算的消光系数存在明显偏差,尤其是在低能见度条件下。基于试验数据,推导了一种以可见光能见度为输入的消光系数计算公式,对估计云雾环境下近红外光辐射的衰减特性具有重要参考价值。 相似文献
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Liquid water fade margin requirements for infrared and millimeter wave runway imaging sensors in fog
Robert E. Marshall David A. de Wolf Christos Kontogeorgakis 《Journal of Infrared, Millimeter and Terahertz Waves》1997,18(6):1133-1149
Liquid water content and particle size distribution at each ten meters in the vertical for a deep advection fog and a shallow radiation fog are analyzed to determine the liquid water loss at millimeter and infrared wavelengths. The liquid water fade margin is calculated along a three degree glideslope in each fog from the current height above the runway to the touchdown point. Millimeter wave fade margin requirements are calculated from the vertical distribution of bulk liquid water content and infrared fade margin requirements are predicted from the vertical distribution of dropsize. Fog dropsize distributions for both fog layers are well fitted to a gamma distribution with a median drop diameter of approximately 9 microns. Millimeter wave imaging sensors operating in a shallow radiation fog are shown to require less than 1 dB of one-way liquid water fade margin. In the deep advection fog, one-way liquid water fade margin requirements at 8.6 mm, 6.8 mm, and 3.2 mm are predicted to be 1, 2, and 6.7 dB respectively. In comparison, the one-way liquid water fade margin requirements at near, middle, and far infrared wavelengths are two orders of magnitude greater than at millimeter wavelengths and indicate the fog layers are opaque to infrared imaging sensors even near the touchdown point. The specific attenuations predicted in the two fogs are consistent with previously reported values. 相似文献
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Moyuan Cao Jie Ju Kan Li Shixue Dou Kesong Liu Lei Jiang 《Advanced functional materials》2014,24(21):3235-3240
Although clean drinking water is a basic human need, freshwater scarcity has been identified as a major global problem of the 21st century. Nature has long served as a source of inspiration for human beings to develop new technology. The cactus in the desert possesses a multifunctional integrated fog collection system originating from the cooperation of a Laplace pressure gradient and the wettability difference. In this contribution, inspired by the cactus, an artificial fog collector on a large scale is first fabricated through integrating cactus spine‐like hydrophobic conical micro‐tip arrays with the hydrophilic cotton matrix. The novel cactus‐inspired fog collector can spontaneously and continuously collect, transport, and preserve fog water, demonstrating high fog collection efficiency and promising applications in the regions with drinking water scarcity. Furthermore, the present approach is simple, time‐saving and cost‐effective, which provides a potential device and new idea to solve the global water crisis. 相似文献