Application of an STFT-based filter in ultrasonic signals for strain monitoring

Monitoring mechanical strain is relevant in several applications. Ultrasonic signals in reverberant media can be used to this purpose by observing the peak of the time reversal or cross-correlation signal. In this paper, we propose a modified technique that uses a new reference signal created using a short-time Fourier Transform based filter to increase the sensitivity to strain. This technique was evaluated in experimental signals and effectively produced up to about fivefold more strain-sensitive signals.