航空遥感器光学窗口光机热一体化设计

为减小光学窗口对航空光学遥感器成像质量的影响,对光学窗口的窗口玻璃厚度进行了优化设计。根据强度理论确定了窗口玻璃最小厚度。依据纵掠平壁理论计算出光学窗口外表面的平均对流换热系数;以热光学为基础,仿真了航摄时光学窗口的瞬态温度场分布;计算了光学窗口在热-力耦合作用下不同窗口玻璃厚度时的波像差(PV和RMS),最终确定了矩形光学窗口(290 mm×140 mm)的玻璃厚度为17 mm。试验结果表明:特征频率为60 lp/mm时光学系统传递函数为0.304,并获得了稳定、清晰的航摄图像。成功实现了光学窗口的光机热一体化设计,可为其他航空光学窗口设计提供参考。

Thermal/structural/optical integrated design for optical window in aerial remote sensor

In order to reduce the influence of optical window on imaging quality in aerial remote sensor,the optical window was optimized in glass thickness.The minimum thickness of optical window glass was calculated with strength theory.The convection heat transfer coefficient on outer surface of optical window glass was calculated with the theory of longitudinally sweeping plan mural.Based on the thermal optical analysis,transient state temperature field was emulated,and the optical path in peak to valley value(PV) and root mean square(RMS) error were calculated under the thermal-force coupling condition.Thickness of the optical window(290 mm×140 mm) was determined as 17 mm.The result of practical application shows that the MTF is 0.304 when the characteristics frequency is 60 lp/mm and the stable and distinct image is obtained.The study result shows that thermal/structural/optical integrated design for optical window is achieved successfully,and it provides a reference for the optical window design.