一种激光搜跟器的光学设计

为提高激光搜跟器对地目标的搜索范围和成像分辨率，提出了一种机载平台下的共孔径激光搜跟器扫搜和跟踪目标的方法，并进行了光学系统的设计。激光搜跟器采用捷联的方式固定于飞行器上，提高了其稳定性；激光的出射和回波的接收，采用共孔径的R-C式反射望远系统实现，缩小了其整体尺寸，并提高了成像分辨率；扫描搜索目标采用双光楔组件实现，并提高了搜索频率和扩大了搜索视场；给出了双光楔旋转角和出射光偏转角之间的关系。设计结果表明，当系统通光孔径为φ300 mm，焦距为2 100 mm时，总体尺寸为685 mm，可扫描搜索视场为±5°，成像视场为±0.08°，成像点弥散斑最大为2.417 μm，系统MTF值在50 lp/mm时大于0.4，满足成像要求；当目标距离为3 km时，可搜索范围达到526 m，可实现对4 m大小目标的成像，成像分辨率为2″。

Optical design of a laser tracker

In order to improve the search range and imaging resolution of the ground target by the laser tracker, a method of searching and tracking the target with a common aperture laser tracker under an airborne platform was presented and the optical system was designed. The laser tracker was fixed on the aircraft by strap down, its stability was improved. The R-C reflection telescopic system with common aperture was adopted to emit the laser and receive laser echoes, which reduced the overall size and improved the imaging resolution. The scanning search target was realized by double optical wedge component, and the search frequency was increased and the search field of view was enlarged. The relationship between the rotation angle of double optical wedge and the angle of outgoing optical deflection was given. The design results show that when the aperture of the system is φ300 mm and the focal length is 2 100 mm, the overall size is 685 mm, the search and scan field of view is ±5°, the imaging field is ±0.08°, the maximum size of the imaging spot speckle is 2.417 μm, and the MTF value of the system is greater than 0.4 at 50 lines per millimeter, which meets the imaging requirements. When the target distance is 3 km, the searchable range reaches 526 m, and the four-meter-sized target can be recognized with a imaging resolution of two seconds.