离轴抛物面反射镜模拟空间环境镜面变形分析

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...

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

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.