MORE INFORMATION ON THE CALIBRATION OF SCANNING STYLUS MICROSCOPES BY 2-DIMENSIONAL FAST FOURIER-TRANSFORM ANALYSIS

An analysis of two-dimensional fast Fourier transform from images of periodical lattices (like highly oriented pyrolytic graphite) has been performed to understand and decouple the various parameters which account for distorted images in stylus microscopy. The effects of the various sources of image distortion have been described by means of linear maps and a mathematical approach has been developed to find the various correction coefficients resulting from the Fourier space analysis which restore the correct geometry of the images. Furthermore, the trend analysis of the distortion angle upon the scanning frequency shows the possibility of decoupling the role of ''static'' and ''time dependent'' distortion parameters. This possibility may be used for an a priori prediction of possible distortions in stylus microscopy and thus for a real-time correction of the images during scanning.