抄録
It is necessary to remove the form error of the reference flat from the interferometer datum for improving the accuracy of the spherical profile measurement using interferometers. For this purpose, a new method called the 2 position- 4 point method was proposed. In this method, form error of the reference flat along a closed circle can be removed. Data points along the circle are necessary for the data processing of this method. However, phase-measuring devices in most interferometers are square-grid detectors, and the data need to be conversed to polar grid array. In this paper, a method is presented to improve the accuracy of the data conversion.
