大视场空间目标搜索相机鬼像抑制及试验验证

Ghost Suppression and Experimental Verification of Large Field Space Target Search Camera

大视场空间目标搜索相机光学系统由多片透镜组合而成,杂散光进入视场时在像平面上产生鬼像,对目标提取产生影响,须对鬼像进行抑制。首先,分析了实际搜索相机地面观星试验时月光进视场图片及星点质心数据,确定鬼像区域存在杂点被误提取;然后,根据大视场光学系统特点,结合光学设计软件ZEMAX仿真确定了产生鬼像的原因;最后,提出了在探测器玻璃保护盖上增加光学截止膜的方法来抑制非正常鬼像并进行了观星试验验证。结果表明:增加光学截止膜后搜索相机鬼像区域平均灰度值由78(@8bit)降低到64,能量下降了17.95%;鬼像边缘与中心灰度差由22降低到13,可有效避免鬼像区域杂点被误提取。

The optical system of the large field space target search camera is composed of multiple lenses,when stray light enters the field of view,ghost images will be generated on the image plane,which will affect the target extraction,and ghost images must be suppressed.At first,the image of the moonlight in the field of view and the centroid data of the star point in the ground observation test of the actual search camera are analyzed,and it is determined that the ghost image region has the wrong extraction of the clutter.Then,according to the characteristics of the large field of view optical system,combined with the optical design software ZEMAX simulation,the cause of the ghost image is determined.Finally,the method of adding optical cut-off film on the glass protective cover of the detector is proposed to suppress the abnormal ghost image and verified by the star observation test,and the results showed that after adding the optical cut-off film,the average gray value of the ghost image region of the search camera is reduced from 78(@8bit)to 64,the energy is reduced by 17.95%,and the gray difference between the ghost image edge and the center is reduced from 22 to 13,which can effectively prevent the ghost image region from being extracted by mistake.