Geophysics · 1957 · 20 citations · 0 references
Abstract A simple statistical procedure, based on multiple coincidence of field polarities as indicated by several receptors, offers a criterion of the existence of a signal below the general noise level. As an example, with six receptors in a field where there is a sine wave signal ten decibels below the noise level, there will be twice the number of coincidences that would be obtained for the noise alone. A scheme is shown to illustrate how an electrical system can perform the analysis and present the results continuously.