Abstract: A method and apparatus for processing measurements of an acoustic wave, the acoustic wave being within a member (12) made of a composite material and caused by an impact to the member (12), the method comprising: analyzing the measurements to detect an initial acoustic wave feature; analyzing the measurements to detect the presence of further acoustic wave features, the further features occurring after the initial feature; if there are no further acoustic wave features, determining that the impact to the member (12) has not changed the structure of the member (12); if there are further features, determining a value of a function of the further acoustic wave features; if the determined value satisfies certain criteria, determining that the impact has changed the structure of the member (12); and if the determined value does not satisfy the criteria, determining that the impact has not changed the structure of the member (12).

Abstract: A method and apparatus for processing measurements of an acoustic wave, the acoustic wave being within a member (12) made of a composite material and caused by an impact to the member (12), the method comprising: analysing the measurements to detect an initial acoustic wave feature; analysing the measurements to detect the presence of further acoustic wave features, the further features occurring after the initial feature; if there are no further acoustic wave features, determining that the impact to the member (12) has not changed the structure of the member (12); if there are further features, determining a value of a function of the further acoustic wave features; if the determined value satisfies certain criteria, determining that the impact has changed the structure of the member (12); and if the determined value does not satisfy the criteria, determining that the impact has not changed the structure of the member (12).