To identify coatings and analyze the anti-detection capabilities of camouflage patterns, material samples can be prepared using the super-pixel segmentation method. A spectral polarization imaging system is developed,...To identify coatings and analyze the anti-detection capabilities of camouflage patterns, material samples can be prepared using the super-pixel segmentation method. A spectral polarization imaging system is developed, based on the principle of bidirectional reflectance distribution function(BRDF), to obtain spectral reflection intensities of coatings at full spatial angles, and use polarization images to calculate the refractive index by the Fresnel equation. The index is then coupled into TorranceSparrow model to simulate the spectral scattering intensity to mutually verify the experimental results. The spectral scattering characteristics of standard camouflage patterns are then revealed and pinpoint the signature band and the angle of reflecting sensitivity.展开更多
双向反射分布函数(Bidirectional Reflectance Distribution Function,BRDF)描述地表反射的各向异性分布特征,是定量遥感研究的重要参数。本研究利用ASD Field Spec 4便携式地物光谱仪和多角度观测支架采集查干湖冰封期不同类型积雪和湖...双向反射分布函数(Bidirectional Reflectance Distribution Function,BRDF)描述地表反射的各向异性分布特征,是定量遥感研究的重要参数。本研究利用ASD Field Spec 4便携式地物光谱仪和多角度观测支架采集查干湖冰封期不同类型积雪和湖冰BRDF,并利用Savitzky-Golay滤波法处理光谱数据,基于地面观测数据分析黑冰、白冰、灰冰、蓝冰和雪的BRDF反射特性,同时探索气泡及杂质对冰雪BRDF反射光谱特性的影响。结果显示,湖冰和积雪表面反射率随天顶角的增加而增加,当方位角为0°和45°时,呈现出明显的各向异性。不同种类的湖冰光谱反射率具有共同的变化特征:当波长位于350~600 nm,湖冰反射率随波长的增大而增大,在600 nm附近反射率达到峰值;当波长位于600~1300 nm,反射率随波长增大而减小,直至完全被吸收。对比不同气泡大小的黑冰光谱特性发现,气泡主要影响350~1000 nm范围内的反射率,气泡的存在增加了黑冰反射率。本研究旨在为湖冰遥感反演算法提供实测数据和机理研究。展开更多
金属铝在航空航天、军事国防、电子通信等领域具有重要应用,对铝材料表面光谱偏振散射特性的研究有助于丰富材料的光学信息,能够为铝材料的应用提供数据支撑.首先基于一套传统双向反射分布函数(bidirectional reflectance distribution ...金属铝在航空航天、军事国防、电子通信等领域具有重要应用,对铝材料表面光谱偏振散射特性的研究有助于丰富材料的光学信息,能够为铝材料的应用提供数据支撑.首先基于一套传统双向反射分布函数(bidirectional reflectance distribution function,BRDF)测量装置在近红外波段测量了粗糙铝表面的光谱偏振BRDF,并分析了入射天顶角、粗糙度等因素对测量结果的影响.测量结果表明:入射角、波长、偏振态和表面粗糙度对BRDF有显著影响.其次,分别采用Beckmann分布和指数分布概率密度分布函数建立了BRDF模型,并对实验结果进行了拟合.通过对比能够发现:对于同一样品和相同入射条件,不同的模型能够得到不同的拟合结果;对于不同粗糙度的样品采用不同的模型可能得到更好的拟合结果.展开更多
基金supported by the Jilin Province Science and Technology Development Plan Item (No.20240402068GH)。
文摘To identify coatings and analyze the anti-detection capabilities of camouflage patterns, material samples can be prepared using the super-pixel segmentation method. A spectral polarization imaging system is developed, based on the principle of bidirectional reflectance distribution function(BRDF), to obtain spectral reflection intensities of coatings at full spatial angles, and use polarization images to calculate the refractive index by the Fresnel equation. The index is then coupled into TorranceSparrow model to simulate the spectral scattering intensity to mutually verify the experimental results. The spectral scattering characteristics of standard camouflage patterns are then revealed and pinpoint the signature band and the angle of reflecting sensitivity.
文摘金属铝在航空航天、军事国防、电子通信等领域具有重要应用,对铝材料表面光谱偏振散射特性的研究有助于丰富材料的光学信息,能够为铝材料的应用提供数据支撑.首先基于一套传统双向反射分布函数(bidirectional reflectance distribution function,BRDF)测量装置在近红外波段测量了粗糙铝表面的光谱偏振BRDF,并分析了入射天顶角、粗糙度等因素对测量结果的影响.测量结果表明:入射角、波长、偏振态和表面粗糙度对BRDF有显著影响.其次,分别采用Beckmann分布和指数分布概率密度分布函数建立了BRDF模型,并对实验结果进行了拟合.通过对比能够发现:对于同一样品和相同入射条件,不同的模型能够得到不同的拟合结果;对于不同粗糙度的样品采用不同的模型可能得到更好的拟合结果.
