Noncontact measurement of angular position and angular movement by means of laser goniometer

Abstract. The results of analysis and experimental investigation of a laser goniometer (LG), working in the mode of the noncontact measurement of an object’s angular position, are presented. The important feature of this approach is the very wide range of high-accuracy measurements. In this case, the LG, characterized by the accuracy of ∼0.1 arc sec, has big advantages in comparison to photoelectrical autocollimators which have a rather narrow range of measured angular positions. Our results indicate that the use of a laser dynamic goniometer makes it possible to measure constant angles with an accuracy of 0.05 to 0.1 arc sec in the range of possible angles of 15 to 20 deg. If the measured angle is varying, the residual measurement error contains an additional component, which is equal to ∼0.2 arc sec, induced by the nonflatness of the optical polygon’s faces and by the problems with statistical averaging of the measurement results.