Both Correlation and Morphological Methods of Detecting a Specified Acoustic Signal Propagating Through the Atmosphere

Abstract

Two methods of detecting quasiperiodic signals—the well-known method of calculating correlation coefficients and the method of a morphological analysis that makes it possible to detect signals with variable phases, which is important in isolating signals at long distances from their sources—are compared. The efficiency of a morphological analysis is in solving the problems of isolating quasiperiodic signals against the background of noise that is comparable to or exceeds (in amplitude) the signal under study. These two methods are compared using subwoofer signals recorded in August 2009 at the Scientific Station of the A.M. Obukhov Institute of Atmospheric Physics. The signal frequencies were chosen within a range of 45–130 Hz and the distance to the source was from 0 to 1255 m. Signals were recorded during night and morning hours, which made it possible to study the potentialities of these methods in isolating a desired signal under both disturbed and undisturbed states of the atmosphere (in the absence or presence of noise of different origins).