基于五阶自由曲面垂轴偏移的空间相机变焦方法

变焦光学系统在空间探测领域中有着重要的应用需求，提出了一种基于五阶自由曲面垂轴偏移的变焦方法，实现了具有两倍变焦能力的光学系统模型。分析了五阶自由曲面透镜的变焦原理和像差模型，采用两组五阶自由曲面透镜设计并搭建了伽利略望远系统，通过控制五阶自由曲面透镜的垂轴偏移量，来改变透镜的光焦度。仿真结果分析表明：该方法的变焦曲线具有单调性，且垂轴偏移量在8mm 以内。与传统变焦方法相比，该变焦方法的特点是结构紧凑、变焦连续、控制方法简单，避免了大幅轴向变焦运动，对于可见光、红外空间光学相机轻小型化具有重要的应用价值。

Zooming Method for Space Cameras Based on Lateral Shift of Fifth-Order Free-Form Lenses

Zoom optical system is crucial for space exploration. The zoom method is proposed which is based on the lateral shift of fifth-order free-form Lenses. By this way, a double zoom optical system model is realized. According to the characteristic of fifth-order free-form Lenses, the zoom principle and aberration model are analyzed. The Galilean telescopic system is modeled with two groups of fifth-order free-form lenses. By controlling the lateral shift of the fifth-order free-form lenses, the effective focal length of the fifth-order free-form lenses is changed. The analysis shows that the zoom curve of the method is monotonic and the lateral shift is less than 8mm. Compared with the traditional zoom method, this zoom method is characterized by compact structure, clear principle, continuous zoom and simple control method.