METHOD OF DETERMINING RADIUS OF CURVATURE OF CONCAVE OPTICAL SPHERICAL SURFACE BY OPTICAL RANGING Russian patent published in 2013 - IPC G01B11/255 

FIELD: physics.

SUBSTANCE: in the method, an autocollimation microscope is focused at the centre of curvature of the concave optical spherical surface at a fixed position thereof and the fixed autocollimation microscope. Distance to the concave optical spherical surface is determined by optical ranging using an optical beam passing on the same optical path as the visual beam of the autocollimation microscope. An object is placed at the centre of curvature of the concave optical spherical surface and distance to said object is also determined by optical ranging using an optical beam passing on the same optical path as the visual beam of the autocollimation microscope. The difference between said two distances is found and said difference is the radius of curvature of the concave optical spherical surface.

EFFECT: reduced uncertainty in determining radius when it is impossible to use a precision guide.