Abstract: A method and system for analyzing emission signals emanating from a test medium for the purpose of determining characteristics of the test medium. The system and method utilize adaptive neural processing to prognosticate futurThis invention was made in part with government support under grant No. MSM 8405466, awarded by the National Institute of Health; and under grant No. N0014-85-K-0595, awarded by the Office of Naval Research. The government has certain rights in the invention.

Abstract: A small non-colinear transducer array for omnidirectional acoustic emission monitoring is disclosed. The small transducer array consists of four piezoelectric sensor elements of sufficiently small diameter as to function as essentially point receivers and of sufficient frequency response as to be sensitive to the signals to be detected. The sensor elements of the transducer array are close together and are non-colinear so that the signals received by them can be used for determining the group velocity of acoustic waves on solid plates and on plate-like structures such as shells and pipes, and to permit determination of both the source direction and distance.