菲涅尔透镜光学系统在弹道测量中的应用

目前,间接阴影照相系统多数采用光学透镜或凹面反射镜组成锥形光路或平行光路,但向大口径推广时受到加工难度及造价的限制。而菲涅尔透镜则以其加工方便、口径极易扩大且价格低廉的特点,显示了其它光学系统无法比拟的优点。本文介绍菲涅尔透镜的基本原理及目前在弹道流场显示中已开拓的几种用途;分析了加工误差对光学质量的影响。大量的拍摄结果表明,清晰度满足要求。同时亦指出了菲涅尔透镜的使用局限性。

The Applications of Fresnel Lens Optical Systems in Ballistic Measurements

At present most indirect shadow photographic systems useoptical lens or concave reflection mirrors to make up conical light paths orparallel light paths. But, they are restricted for extending to large caliberby machining precision and costs. Fresnel lens have characteristics of easymachining, extending to large caliber and less costs, have displayed theineontestable advantages over other optical systems. This Paper introduces the basic principles of Fresnel Iens and someapplications for the visualization of ballistic flow field. The machiningerrors affecting the optical quality of lens have beeh analyzed, A lot ofphotographic results show that the clarity requirments could be matched,More over, the limitions of Fresnel lens in ballistic measurements havebeen presented.