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For designing camouflage of ground metal target against millimeter wave(MMW) passive detections,based on the radiation and reflection theories related to MMW passive detection and an assumption of high frequency approximation,simplified models of two kinds of ground metal targets are established.Analysis indicates that the reflection from ground is the leading factor on a ground metal target’s radiant temperature.In an 8-mm imaging experiment,the uneven distribution of radiant temperatures in horizontal and vertical metal plates is directly perceived.In a radiometer experiment,two positions of a radiometer device are utilized to obtain the radiant temperatures of a horizontal metal in two different grounds(made of asphalt and metal net respectively),which are 295.41 K and 301.55 K,respectively.The experimental results are close to the analytical results calculated from the proposed simplified models,which are 306 K and 296 K,respectively.According to the simplified models,different parts of a vertical plate receive incident MMW of different angles from the asphalt background.The radiant temperature of a vertical metal plate obtained from a radiometer experiment at night is 307 K,and it is in coherent with 304.22 K,the result from calculation using the simplified model of vertical plate.Both the analytic results and the experimental results agree with the uneven distribution of radiant temperature. 相似文献
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为了分析目标具体特征对其在一定背景下的可见性影响,设计了利用配对比较法来定量分析目标可见性的影响因素的方法。采集目标背景图像,通过图像处理的方式形成一组目标特性逐渐变化的图片,对这些图片进行心理物理学配对比较判别实验。按照这样的方法对一组亮度渐变图片和色度渐变图片进行了实验和分析,得到了图片中目标可见性对其亮度和色度的依赖关系。这一结果证实了配对比较法在定量分析目标可见性过程中的适用性。 相似文献
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发现扫描隧道显微镜可对聚苯乙烯超微粒子进行观察,用水悬浮液及苯饱和溶液使聚苯乙烯表面溶胀后,都可得到清晰的STM像,并首次从溶胀表面的高分辨率STM像观察到高分子链的精细结构和链的镶嵌式自组装形式。 相似文献
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发现扫描隧道显微镜可对聚苯乙烯超微粒子进行观察。用水悬浮液及苯饱和溶液使聚苯乙烯表面溶胀后,都可得到清晰的STM像,并首次从溶胀表面的高分辨率STM像观察到高分子链的精细结构和链的镶嵌式自组装形态。 相似文献