This Letter concerns the determination of the correlation functions of a zero mean random process from a set of measured specimens. While examining some properties of rough optical surfaces, we noted that interferometric surface profile measurements do not provide the location of the zero mean reference level for each of the samples collected, so that the dc level of each sample is known. A similar problem may arise in temporal signal analysis if samples of signal variations only are recorded.
© 1977 Optical Society of America
E. L. O’Neill and A. Walther, "A problem in the determination of correlation functions," J. Opt. Soc. Am. 67, 1125-1125 (1977)