Research Article
Fractional Fourier Transform for Ultrasonic Chirplet Signal Decomposition
Table 6
Estimated parameters of chirplets (crack D).
| | TOA (us) | Center frequency (MHz) | Amplitude (m-Volt) |
| Reference signal | 34.583 | 9.42 | 363.3 | 34.725 | 10.60 | 54.4 |
| Refracted angle 0° | 38.776 | 10.38 | 4.64 | 38.891 | 13.06 | 0.50 |
| Refracted angle 30° | 39.777 | 7.68 | 0.50 | 40.040 | 9.10 | 0.14 | 39.674 | 12.57 | 0.18 | 39.861 | 2.18 | 0.03 |
| Refracted angle 45° | 40.677 | 9.85 | 0.17 | 40.956 | 9.85 | 0.07 | 40.675 | 4.51 | 0.04 | 40.620 | 15.65 | 0.03 |
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