温度对星敏感器光学系统像面位移的影响研究

光学系统的温度变化会使系统产生像面位移。根据镜面材料特性公式,选用铝合金作为星敏感器的镜筒,透镜组选用ψ值大的材料,并进一步通过I-DEAS软件进行了计算验证。在此基础上根据矩阵光学理论和温度的变化推导出了含有多个光学器件的星敏感器像面位移计算公式,并运用该公式对一个特定的星敏感器光学系统的像面位移进行了计算。结果发现,光学系统从一个温度均匀分布状态变到另一个温度均匀分布状态的温差越大,像面位移量的绝对值越大。同时还发现,对此星敏感器成像精度影响最大的透镜是第4块、第5块和第6块,明显地减少了在热补偿条件下的系统像面位移。

Study of effect of temperature change on the image shifting of the optical system in star sensor

The temperature change of the optical system causes the image shifting.First,the optical materials of the drawtube and lens are determined by lens material characteristic formula,and the study shows that it is better to choose aluminum alloys and bigger ψ as the materials of the drawtube and lens respectively.The above conclusion is further validated by the I-DEAS software.Based on this,according to the matrix optics theory,the star sensor's image shifting formula is deduced for the change of temperature of the system.The image shifting of a special optical system in star sensor is calculated by the formula.The results show image shifting increases with the increase in the temperature difference when the uniform temperature distribution state of the system changes to another one.The 4th to 6th lens cause much more effects on the precision of the star sensor than another lens,and the image shifting decreases obviously on thermal compensation.