Dresden 2017 – scientific programme
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O: Fachverband Oberflächenphysik
O 87: Metal Substrates: Structure, Epitaxy and Growth
O 87.4: Talk
Thursday, March 23, 2017, 11:30–11:45, WIL C307
Correlogram Correlation for Surface Topology Evaluation by White Light Interferometry — •Ilia Kiselev1, Michael Drexel1, Egor Kiselev2, and Michael Hauptmannl1 — 1Breitmeier Messtechnick GmbH, Englerstr. 24, 76275 Etlingen — 2Physikalisches Institut, Karlsruhe Institut of Technology, Wolfgang-Gaede-Str. 1, 76131 Karlsruhe
Established methods to gauge the surface height by the white light interferometry do not use the full Information contained in a correlogram. As the result, the envelope evaluation methods suffer from susceptibility to noise, whereas the phase methods are prone to the *2-pi ambiguity*. The suggestion here is to determine the surface position via the correlation of the local correlogram with a reference correlogram. It is easy to see that the method is to be the most stable to noises of different kinds: it benefits using the complete correlogram information. Theoretical Cramer-Rao estimations as well as evaluations of measured data samples demonstrates the prevalence of the method. Tolerance to noise of this method is by more than one order of magnitude higher, than that of the envelope methods and exceeds that of the phase method; available data which indicates the 2-pi jumps by phase method provide smooth results by this one. Another advantage of the suggested method is the immediate availability of a suitability criterion for a local correlogram * the correlation coefficient with the reference one.