Do we need all the frequency components of a fringe signal to obtain position information in a vertical scanning wideband interferometer?

Using a wideband light source based vertical scanning interferometer, we can obtain the position information of an object from the peak value of the envelope of the interference fringe signal. For the reconstruction of the envelope of this signal, it is necessary to select its frequency components; however, the question that naturally arises is whether there is a need to select all the frequency components of the signal to determine the position of the envelope peak. Based on our proposed method and subsequent optical experiments, we find that the peak position of the envelope can be estimated using only the frequency pairs that have high signal-to-noise ratios. Thus, this observation can be applied to not only improve the measurement performance of wideband scanning interferometers, but also to enable more complex and accurate optical metrology.