PSD Testing

Power Spectral Density (PSD) of the ISMAT system was validated based on Parseval’s Theorem [19]. Numerically generated profiles and real surface profiles were used to test the ISMAT's PSD implementation. RMS (Rq) values of these profiles are equal to the square root of the twice area under their Power Spectral Density Curve [20].  Figure belows shows a 0.1 mm wavelength sinusoidal profile and its PSD curve.

0.1 mm wavelength sinusoidal profile has Rq =0.0707 micron. This is equal to the square root of the twice area under its PSD curve.
Calculated PSD curve of 0.1 mm wavelength sinusoidal profile by ISMAT