平面のうねり形状の測定に関する研究(第2報)

形状測定とディジタルフィルタ

抄録

The point of view of digital filter was applied to the problem of surface undulation measurement. As a result the error was discussed in spatial frequency domain, of tangent method, inclination method and their modification. In spatial frequency domain, error of measurement is estimated clearly. Inclination method correspond to the measurement that leg width is equal to sampling interval and integrated by midpoint formula. The method except condition one by one from inclination method means to 2 points method. 2 points method opened up a prospect that avoid the probrem of aliasing. Knowledge of transfer function makes elevation of accuracy possible by inverse filtering. In case that data is uncontinuous at both ends, insert data made by spline function restrain of Gibbs phenomenon and makes high accuracy.