The formation of light templates for large-sized objects using the diffraction optics methods

The method of light template formation for large-sized objects (from several to tens of meters) such as antennas has been developed on the basis of diffraction optical elements (DOE). The essence of this method consists in creation into a space of light markers in the form of focused laser beams, the foci of which and intersection points lie on the paraboloid surface describing the shape of the antenna. This approach provides markers assignment with high accuracy (error is 0.02-0.2 mm at a distance of 20-30 m). The calculation of the basic DOE parameters for antenna with the diameter of 25 m is given. Experimental results on light templates formation using two DOE sets generating 19 and 288 light points are presented. It has been shown that under specified choice of optical system parameters for forming the light templates one can visually detect the deviation of the object surface by the value of ± 1 mm. The proposed method can greatly facilitate the implementation of labor-intensive assembly operations, adjustment as well as inspection the shape of large-sized antennas in shop conditions.