Iterative algorithm for absolute planarity calibration in three-flat test.

An iterative algorithm is presented to calibrate the shapes of the reference surfaces in three-flat test. Three measurements in three-flat test determine the even part of the flat surfaces. The odd part can be obtained by adding one or more rotation measurements and using analytical recovery algorithm. Here we present an iterative algorithm to obtain the odd part instead of special analytical recovery algorithm. The iterative algorithm is purely numerical, and only involved in data rotation operation. A simulation experiment proves the validity and high accuracy of the proposed algorithm method.