Two-Level Correlation on an Analog Computer

It has been known for some time that an approximate correlation analysis of a random process can be performed using quantized values of the signal. The simplest form possible is a two-level correlation, wherein merely the polarities of the process at two sampling times, T 1 and T 2 =T 1+τ are compared. This report describes a study of this technique, using analog-computer circuitry; it is an interesting example of how existing electronic analog computers can implement essentially digital functions in making accurate statistical measurements.