FOCAL LENGTH AND DISTORTION OF 180/185 LOW LIGHT CALIBRATING AND TRACKING TV OPTICAL SYSTEM DETERMINED BY DKM3 -THEODOLITE
用DKM_3经纬仪测量180/185微光标校跟踪电视光学系统的焦距和畸变

The fine optical instruments used for aerial photographic survey, geodetic survey and celestial body survey and so on must be calibrated and checked completely before leavinng the factory, so as to determine their focal lengths and distortions, and give out corrected values of distortions in permissible range. The paper deals with focal length and distortion of TV optical system determ ined by the high-precision theodolite, and analyzes measuring accuracy, and it puts forward a few principal problems to be noticed.