目的解决月面着陆器在下降过程中可能得不到足够的匹配点进行着陆区地形恢复的问题。方法基于特征边缘线梯度比例约束的明暗恢复形状(shape from shading)算法。首先以Lommel-Seeliger模型模拟月表反射情况,建立辐照度方程;然后以地形...目的解决月面着陆器在下降过程中可能得不到足够的匹配点进行着陆区地形恢复的问题。方法基于特征边缘线梯度比例约束的明暗恢复形状(shape from shading)算法。首先以Lommel-Seeliger模型模拟月表反射情况,建立辐照度方程;然后以地形特征边缘提取结果为基础,经过最小二乘拟合与表面光滑模型约束后,演化得到剩余影像点的梯度比例因子,实现对辐照度方程的正则化约束。结果经过测试得到模拟影像的平均相对恢复精度可以达到-0.199,真实影像月面可以达到0.051和0.022。结论本文算法能够有效地进行3维地形恢复,且恢复精度优于经典SFS算法中对实际地形恢复效果最好的Tsai算法。展开更多
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 appro...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.展开更多
文摘目的解决月面着陆器在下降过程中可能得不到足够的匹配点进行着陆区地形恢复的问题。方法基于特征边缘线梯度比例约束的明暗恢复形状(shape from shading)算法。首先以Lommel-Seeliger模型模拟月表反射情况,建立辐照度方程;然后以地形特征边缘提取结果为基础,经过最小二乘拟合与表面光滑模型约束后,演化得到剩余影像点的梯度比例因子,实现对辐照度方程的正则化约束。结果经过测试得到模拟影像的平均相对恢复精度可以达到-0.199,真实影像月面可以达到0.051和0.022。结论本文算法能够有效地进行3维地形恢复,且恢复精度优于经典SFS算法中对实际地形恢复效果最好的Tsai算法。
基金supported by Jiangsu Key laboratory of Spectral Imaging&Intelligent Sense(Nanjing University of Science and Technology)(30920130122XXX)
文摘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.
