离轴抛物面反射镜模拟空间环境镜面变形分析  

Surface deformation analysis of off-axial paraboloidal mirror under space simulation conditions

作　　者：肖庆生[1] 许杰[2] 杨林华[2] 

机构地区：[1]中国空间技术研究院,北京100094 [2]北京卫星环境工程研究所,北京100094

出　　处：《光学技术》2011年第2期153-157,共5页Optical Technique

摘　　要：在卫星红外多光谱扫描仪模拟空间环境辐射定标试验中,环境模拟器舱内的稳、瞬态温度场会给光学系统成像质量带来影响。以试验中的实测温度变化作为温度载荷,借助有限元软件,分析了定标系统中通光孔径为Φ400mm的离轴抛物面主镜的温度场分布和热弹性变形。选用在单位圆内正交的Zernike多项式为拟合基函数,通过坐标变换,将抛物镜表面坐标转换为完整抛物面坐标,而后从矛盾方程组入手,应用Householder变换,把系数矩阵正交三角化,求解拟合系数,完成波面拟合。拟合前后各离散点的PV值由1.59×10-5 m变为1.5626×10-5 m,RMS值由3.7159×10-6 m变为3.7144×10-6 m。将拟合结果导入ZEMAX软件中,导入前后,离轴抛物面反射镜波前像差PV值由0改变为0.018λ(λ=632.8nm)。应用该方法进行了镜面变形分析,结果表明,拟合精度高,并可以分析任意面形、形状的光学表面。In radiometric calibration test for satellite multi-spectral scanner under simulation space conditions,the steady or instantaneous temperature field brings much effect to imaging quality of optical system.The temperature of nodes collected in test is added to FEM;the distribution of temperature field and thermal deformation of off-axial paraboloidal mirror whose caliber is Φ400mm in optical system are calculated.Based on orthogonal Zernike annular polynomials used as basic functions over an unit annulus,the coordinates of off-axial paraboloidal mirror surface are transformed to the coordinates of whole paraboloidal mirror surface;Then,the matrix of inconsistent equation group is orthogonalized and triangulated by the using of the Householder transformation method,and the Zernike coefficients can be worked out by using a back substitution technique,and the wave-front fitting can be completed.Before fitting,the previous PV（peak-vale） value is 1.59×10-5m and the RMS（root-mean-square） value is 3.7159×10-6m.After fitting,they become 1.5626×10-5m and 3.7144×10-6m respectively.The fitting results are imported into ZEMAX software and the PV value of off-axial paraboloidal mirror are 0 and 0.018λ（λ=632.8nm） respectively.Optical surfaces with any shapes can be fitted by this method and they are precise.

关 键 词：离轴抛物镜 波面拟合 ZERNIKE多项式 像质评价 

分 类 号：TH706[机械工程—仪器科学与技术]