Chirplet transform for ultrasonic signal analysis and NDE applications

In this investigation, the chirplet transform is introduced as a means to obtain not only time-frequency representation, but also to estimate the echo amplitude, time of arrival, center frequency, bandwidth, phase, and chirp rate of multiple interfering ultrasonic echoes. This transformation can be used for signal decomposition and successive parameter estimation of multiple interfering echoes. It has been shown that by using both simulated chirp signals and the ultrasonic experimental data, the chirplet signal decomposition algorithm performs robustly, yields accurate echo estimation and results in SNR enhancements. Numerical and analytical results show that the algorithm is efficient and successful in precise signal representation. This type of study addresses a broad range of applications including flaw detection, deconvolution, object classification, velocity measurement, and ranging systems.